Details

An issue was discovered in PostCSS before 8.4.31. It affects linters using PostCSS to parse external Cascading Style Sheets (CSS). There may be \r discrepancies, as demonstrated by @font-face{ font:(\r/*);} in a rule.

This vulnerability affects linters using PostCSS to parse external untrusted CSS. An attacker can prepare CSS in such a way that it will contains parts parsed by PostCSS as a CSS comment. After processing by PostCSS, it will be included in the PostCSS output in CSS nodes (rules, properties) despite being originally included in a comment.

Severity

• CVSS Score: 5.3 / 10 (Medium)
• Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

References

• https://nvd.nist.gov/vuln/detail/CVE-2023-44270
• https://github.com/postcss/postcss/commit/58cc860b4c1707510c9cd1bc1fa30b423a9ad6c5
• https://github.com/postcss/postcss/blob/main/lib/tokenize.js#L25
• https://github.com/postcss/postcss/releases/tag/8.4.31
• https://github.com/github/advisory-database/issues/2820
• https://lists.debian.org/debian-lts-announce/2024/12/msg00025.html
• https://github.com/advisories/GHSA-7fh5-64p2-3v2j

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

v8.4.31

Compare Source

• Fixed \r parsing to fix CVE-2023-44270.

v8.4.30

Compare Source

• Improved source map performance (by Romain Menke).

v8.4.29

Compare Source

• Fixed Node#source.offset (by Ido Rosenthal).
• Fixed docs (by Christian Oliff).

v8.4.28

Compare Source

• Fixed Root.source.end for better source map (by Romain Menke).
• Fixed Result.root types when process() has no parser.

v8.4.27

Compare Source

• Fixed Container clone methods types.

v8.4.26

Compare Source

• Fixed clone methods types.

v8.4.25

Compare Source

• Improve stringify performance (by Romain Menke).
• Fixed docs (by @​vikaskaliramna07).

v8.4.24

Compare Source

• Fixed Plugin types.

v8.4.23

Compare Source

• Fixed warnings in TypeDoc.

v8.4.22

Compare Source

• Fixed TypeScript support with node16 (by Remco Haszing).

v8.4.21

Compare Source

• Fixed Input#error types (by Aleks Hudochenkov).

v8.4.20

Compare Source

• Fixed source map generation for childless at-rules like @layer.

v8.4.19

Compare Source

• Fixed whitespace preserving after AST transformations (by Romain Menke).

v8.4.18

Compare Source

• Fixed an error on absolute: true with empty sourceContent (by Rene Haas).

v8.4.17

Compare Source

• Fixed Node.before() unexpected behavior (by Romain Menke).
• Added TOC to docs (by Mikhail Dedov).

v8.4.16

Compare Source

• Fixed Root AST migration.

v8.4.15

Compare Source

• Fixed AST normalization after using custom parser with old PostCSS AST.

v8.4.14

Compare Source

• Print "old plugin API" warning only if plugin was used (by @​zardoy).

v8.4.13

Compare Source

• Fixed append() error after using .parent (by Jordan Pittman).

v8.4.12

Compare Source

• Fixed package.funding to have same value between all PostCSS packages.

v8.4.11

Compare Source

• Fixed Declaration#raws.value type.

v8.4.10

Compare Source

• Fixed package.funding URL format.

v8.4.9

Compare Source

• Fixed package.funding (by Álvaro Mondéjar).

v8.4.8

Compare Source

• Fixed end position in empty Custom Properties.

v8.4.7

Compare Source

• Fixed Node#warn() type (by Masafumi Koba).
• Fixed comment removal in values after ,.

v8.4.6

Compare Source

• Prevented comment removing when it change meaning of CSS.
• Fixed parsing space in last semicolon-less CSS Custom Properties.
• Fixed comment cleaning in CSS Custom Properties with space.
• Fixed throwing an error on .root access for plugin-less case.

v8.4.5

Compare Source

• Fixed raws types to make object extendable (by James Garbutt).
• Moved from Yarn 1 to pnpm.

v8.4.4

Compare Source

• Fixed custom syntax without source.offset (by @​romainmenke).

v8.4.3

Compare Source

• Fixed CssSyntaxError types (by @​romainmenke).

v8.4.2

Compare Source

• Fixed Node#source.offset (by Ido Rosenthal).
• Fixed docs (by Christian Oliff).

v8.4.1

Compare Source

• Fixed whitespace preserving after AST transformations (by Romain Menke).

v8.4.0: 8.4 "President Camio"

Compare Source

PostCSS 8.4 brought ranges for warnings and errors, smaller node_modules size, lazy parsing to avoid PostCSS does nothing warning, and TypeScript fixes.

Thanks to Sponsors

This release was possible thanks to our community.

If your company wants to support the sustainability of front-end infrastructure or wants to give some love to PostCSS, you can join our supporters by:

• Tidelift with a Spotify-like subscription model supporting all projects from your lock file.
• Direct donations in PostCSS & Autoprefixer Open Collective.

Rages for Errors and Warnings

@​adalinesimonian, the author of amazing Stylelint extension for VS Code, added ranges to errors and warnings.

result.warn(msg, { index }) // One character warning at index
result.warn(msg, { endIndex }) // Starts at node start, ends at endIndex
result.warn(msg, { index, endIndex }) // Starts at index, ends at endIndex
result.warn(msg, { start }) // Starts at start, ends at node end
result.warn(msg, { end }) // Starts at node start, ends at end
result.warn(msg, { start, end }) // Starts at start, ends at end
result.warn(msg, { word }) // Starts at word location, ends at word index + length

It will improve DX in the IDE extension.

Lazy Parsing

Previously, we found that many tools run PostCSS even if the developer didn’t pass any PostCSS plugins. Parsing is the most expensive step in CSS processing. It led to a waste of resources without any reason.

We tried to resolve the problem by adding a PostCSS does nothing warning. But it didn’t force tool authors to be more careful with user’s resources.

If PostCSS sees that tool call it without passing plugins (or changing parser/stringifier), PostCSS will not parse CSS (until toll will call Result#root). In 8.4, @​bogdan0083 (with the help of @​WilhelmYakunin) tries to solve the problem in another way. It allows us to save resources and remove the PostCSS does nothing warning.

// No plugins, we do not parse CSS
let result = await postcss().process(css, { from })
result.css // Is the same string passed to process()
result.map // Special 1-to-1 source map
result.root // CSS will parsed only here

Install Size Reduction

With ≈60M weekly downloads, PostCSS has responsibility for the world’s resource spending.

Together with @​7rulnik we reduced source-map-js size. It is transitive dependency of PostCSS.

In 8.4, we moved to a fixed version of source-map-js, which reduced the postcss size in your node_modules from ≈1 MB to 0.3 MB. With the huge popularity of PostCSS, it will free a lot of resources on our CIs.

Migration from Jest to uvu

@​kimoofey refactored all tests from the popular Jest framework to small and fast uvu.

It will not affect end-users. However, it reduced our node_modules size by 33 MB and made tests twice faster (yarn install & yarn unit: 24 → 13 seconds).

TypeScript Fixes

• Added Processor types.
• Added Stringifier types (by @​43081j).
• Fixed types Root and Document in result values (by @​43081j).
• Fixed Node#walkRules() types (by @​hudochenkov).

Other Changes

• Fixed docs (by @​paulshryock).

v8.3.11

Compare Source

• Remove debugging code.

v8.3.10

Compare Source

• Fixed Maximum call stack issue of some source maps (by Yeting Li).

v8.3.9

Compare Source

• Replaced nanocolors to picocolors.
• Reduced package size.

v8.3.8

Compare Source

• Update nanocolors.

v8.3.7

Compare Source

• Replaced colorette to nanocolors.
• Added bug field to package.json (by Christian Oliff).
• Improved docs (by Andrew Bruce and Paul Shryock).

v8.3.6

Compare Source

• Fixed column in missed semicolon error (by @​Gusted).

v8.3.5

Compare Source

• Fixed broken AST detection.

v8.3.4

Compare Source

• Fixed broken AST detection.

v8.3.3

Compare Source

• Fixed broken AST on postcss dependency duplication in custom parsers.

v8.3.2

Compare Source

• Update changelog.

v8.3.1

Compare Source

• Remove debugging code.

v8.3.0: 8.3 "Duke Murmur"

Compare Source

PostCSS 8.3 improved source map parsing performance, added Node#assign() shortcut, and experimental Document node to AST.

Thanks to Sponsors

This release was possible thanks to our community.

If your company wants to support the sustainability of front-end infrastructure or wants to give some love to PostCSS, you can join our supporters by:

• Tidelift with a Spotify-like subscription model supporting all projects from your lock file.
• Direct donations in PostCSS & Autoprefixer Open Collective.

Source Map Performance

Because PostCSS needs synchronous API, we can’t move from the old `source-map 0.6 to 0.7 (many other open-source projects too).

@​7rulnik forked source-map 0.6 to source-map-js and back-ported performance improvements from 0.7. In 8.3 we switched from source-map to this source-map-js fork.

You map see 4x performance improvements in parsing map from processing step before PostCSS (for instance, Sass).

Document Nodes

Thanks to @​gucong3000, PostCSS already parse CSS from HTML and JS files (CSS-in-JS templates and objects).

But his plugin need big updates. @​hudochenkov from stylelint team decided to create new parsers for styles inside CSS-in-JS, HTML, and Markdown.

He suggested adding new Document node type to PostCSS AST to keep multiple Root nodes inside and JS/HTML/Markdown code blocks between these style blocks.

const document = htmlParser(
 '<html><style>a{color:black}</style><style>b{z-index:2}</style>'
)
document.type //=> 'document'
document.nodes.length //=> 2
document.nodes[0].type //=> 'root'

This is an experimental feature. Some aspects of this node could change within minor or patch version releases.

Node#assign() Shortcut

The creator of famous postcss-preset-env and many other PostCSS tools, @​jonathantneal suggested a nice shortcut to change multiple properties in the node:

decl.assign({ prop: 'word-wrap', value: 'break-word' })

v8.2.15

Compare Source

• Fixed list type definitions (by @​n19htz).

v8.2.14

Compare Source

• Removed source-map from client-side bundle (by Barak Igal).

v8.2.13

Compare Source

• Fixed ReDoS vulnerabilities in source map parsing (by Yeting Li).

v8.2.12

Compare Source

• Fixed package.json exports.

v8.2.11

Compare Source

• Fixed DEP0148 warning in Node.js 16.
• Fixed docs (by @​semiromid).

v8.2.10

Compare Source

• Fixed ReDoS vulnerabilities in source map parsing.
• Fixed webpack 5 support (by Barak Igal).
• Fixed docs (by Roeland Moors).

v8.2.9

Compare Source

• Exported NodeErrorOptions type (by Rouven Weßling).

v8.2.8

Compare Source

• Fixed browser builds in webpack 4 (by Matt Jones).

v8.2.7

Compare Source

• Fixed browser builds in webpack 5 (by Matt Jones).

v8.2.6

Compare Source

• Fixed Maximum call stack size exceeded in Node#toJSON.
• Fixed docs (by inokawa).

v8.2.5

Compare Source

• Fixed escaped characters handling in list.split (by Natalie Weizenbaum).

v8.2.4

Compare Source

• Added plugin name to postcss.plugin() warning (by Tom Williams).
• Fixed docs (by Bill Columbia).

v8.2.3

Compare Source

• Fixed JSON.stringify(Node[]) support (by Niklas Mischkulnig).

v8.2.2

Compare Source

• Fixed CSS-in-JS support (by James Garbutt).
• Fixed plugin types (by Ludovico Fischer).
• Fixed Result#warn() types.

v8.2.1

Compare Source

• Fixed list type definitions (by @​n19htz).

v8.2.0: 8.2 "Prince Orobas"

Compare Source

PostCSS 8.2 added a new API to serialize and deserialize CSS AST to JSON.

import { parse, fromJSON } from 'postcss'
let root = parse('a{}', { from: 'input.css' })
let json = root.toJSON()
// save to file, send by network, etc
let root2 = fromJSON(json)

Thanks to @​mischnic for his work.

v8.1.14

Compare Source

• Fixed parser performance regression.

v8.1.13

Compare Source

• Fixed broken AST after moving nodes in visitor API.

v8.1.12

Compare Source

• Fixed Autoprefixer regression.

v8.1.11

Compare Source

• Added PostCSS update suggestion on unknown event in plugin.

v8.1.10

Compare Source

• Fixed LazyResult type export (by Evan You).
• Fixed LazyResult type compatibility with Promise (by Anton Kastritskiy).

v8.1.9

Compare Source

• Reduced dependencies number (by Bogdan Chadkin).

v8.1.8

Compare Source

• Fixed LazyResult type compatibility with Promise (by Ludovico Fischer).
• Fixed HTTPS links in documentation.

v8.1.7

Compare Source

• Fixed import support in TypeScript (by Remco Haszing).

v8.1.6

Compare Source

• Reverted package.exports Node.js 15 fix.

v8.1.5

Compare Source

• Fixed Node.js 15 warning (by 沈鸿飞).

v8.1.4

Compare Source

• Fixed TypeScript definition (by Arthur Petrie).

v8.1.3

Compare Source

• Added package.types.

v8.1.2

Compare Source

• Fixed API docs (by Arthur Petrie).
• Improved plugin guide (by Yunus Gaziev).
• Prepared code base for Deno support (by Oscar Otero).

v8.1.1

Compare Source

• Fixed parser performance regression.

v8.1.0: 8.1 "Duke Gemory"

Compare Source

PostCSS 8.1 fixed the new visitor API from the 8.0 release.

We fixed Root and RootExit re-calling on children's changes. And now visitors will visit the parent again if nested children were changed.

We added Once and OnceExit events, which will not be called again on node changes. You can use them to lint files or collect statistics:

module.exports = {
 postcssPlugin: 'postcss-linter',
 OnceExit (root) {
 lint(root)
 }
}
module.exports.postcss = true

We updated Migration guide according to new changes.

v8.0.9

Compare Source

• Replace prototype in PostCSS 7 nodes instead of recreating them.
• Added missed Transformer to exported types (by Pierre-Marie Dartus).

v8.0.8

Compare Source

• Fix 8.0.7 regression on PostCSS 7 nodes converting (by Adam Wathan).

v8.0.7

Compare Source

• Fixed compatibility issue with mixin AST with PostCSS 7 and 8 nodes.
• Added migration guide translation to Chinese to the warning.

v8.0.6

Compare Source

• Fixed child adding methods in Container.

v8.0.5

Compare Source

• Update changelog.

v8.0.4

Compare Source

• Fixed Cannot read property 'line' of null error.
• Fixed source map support for declarations.

v8.0.3

Compare Source

• Fixed client-side bundling support.

v8.0.2

Compare Source

• Fixed plugin packs support.

v8.0.1

Compare Source

• Updated Processor#version.

v8.0.0: 8.0 "President Ose"

Compare Source

PostCSS 8.0 brings new plugin API, node_modules size reduction, better source map support, and CSS parser improvements.

Check out a day-by-day diary of PostCSS 8.0 development process.

See Migration Guides for end-users and for plugin developers.

Thanks to Sponsors

With more than 100 M downloads per month, it becomes hard to support PostCSS in free time. For instance, getting the 8.0 release ready took 4 months of work.

This release was possible thanks to out community. Tailwind CSS, De Voorhoede, InVision AG, Brainbow, and many individual contributions.

If your company wants to support the sustainability of front-end infrastructure or just wants to give some love to PostCSS, you can join our supporters by:

• Tidelift with a Spotify-like subscription model and supporting all projects from your lock file.
• Direct donations in PostCSS & Autoprefixer Open Collective.

Breaking Changes

We try to avoid any breaking changes for end-users:

• PostCSS 8 dropped Node.js 6.x, 8.x, 11.x, and 13.x versions support. All these versions have no security updates anymore.
• We now serve ES6+ sources in the npm package without Babel compilation. If you are creating tools like CodePen and put PostCSS into the client-side JS bundle, you may need to run Babel on node_modules/postcss for old browsers.
• We removed rarely used postcss.vendor API.

New Plugin API

The biggest change in PostCSS 8 is a new plugin API. Thanks to @​BondarenkoAlex for big help in creating a new API.

module.exports = () => {
 return {
 postcssPlugin: 'postcss-will-change',
 Declaration: {
 'will-change': (decl, { Declaration }) => {
 decl.cloneBefore(
 new Declaration({ prop: 'backface-visibility', value: 'hidden' })
 )
 }
 }
 }
}
module.exports.postcss = true

We know that rewriting old plugins will take time, but the new API will improve the end-user’s experience and make life easier for plugin developers:

• With new API, all plugins can share a single scan of the CSS tree. It makes CSS processing up to 20% faster.
• Because npm often duplicates dependencies, you may have many postcss duplicates in your node_modules. New API fixes this problem.
• Plugins will re-visit changed nodes to reduce compatibility issues between plugins. Now the order of plugins in your PostCSS config will be less important.
• New API is close to Babel’s visitor API.

These resources will help plugin developers in API migration:

• The Migration Guide
• Writing a PostCSS Plugin
• We have a Gitter chat open for all questions related to plugin migration.

PostCSS development guidelines were also changed:

• Now it is prohibited to create own AST on top of PostCSS AST classes since it could lead to painful bugs due to the usage private APIs.
• Plugins and runners must have postcss in peerDependencies.

New Website without React

Previously PostCSS used a React-based framework for the project's website. Since we have a static website, we decided to migrate to a React-free framework and got good performance improvements:

• 360 → 20 ms for Max Potential First Input Delay
• 3.3 → 1.5 seconds for First CPU Idle
• 3.3 → 1.5 seconds for Time to Interactive

Check out postcss.org and new API docs that feature the awesome alchemy-inspired design by @​okonet.

We also removed Google Analytics tracking scripts and encourage other open source projects to be an example in caring about user’s privacy and performance.

Parser Improvments

Did you know that all examples below are valid CSS?

:root {
 --empty: ;
 --JSON: [1, "2", {"three": {"a":1}}, [4]];
 --javascript: function(rule) { console.log(rule) };
}
@​supports (--element(".minwidth", { "minWidth": 300 })) {
 [--self] {
 background: greenyellow;
 }
}

Now PostCSS parses even those rare edge cases correctly. Thanks to Tailwind CSS and Prettier teams for adding more cases to our CSS parser tests collection.

Note that now --roundMixin: { border-radius: 8px } will be parsed as a Declaration with the { border-radius: 8px } value.

Better Source Map Support

We have added support for two new source map formats: Index map and JSON (data:application/json).

PostCSS 8 is now much closer to the source map spec. Thanks to the Google team for reports:

• We now treat sources in map as URLs instead of file paths.
• We now resolve sources relative to map file, not CSS file.

A few source map APIs were added:

• opts.maps.absolute = true option for absolute paths in source map.
• opts.maps.annotation = (file, root) => url for a dynamic path to source map.
• Node#origin() now returns position.url in addition to position.file for compatibility with absolute URLs in source map’s sources.

API Changes

We have added ES modules support and now we export all classes from the main entry:

import { CssSyntaxError, parse } from "postcss"

@​graberzz added Node#source.offset in addition to line and column.

CSS Custom Properties and Sass-like $-variables now have a special Declaration#variable mark:

const root = parse(`
 :root {
 --propery: value;
 }
 $variable: value
`)
root.first.first.variable //=> true
root.last.variable //=> true

TypeScript

PostCSS now has a first-class TypeScript support:

• We moved API docs from JSDoc to TypeDoc. Check out our new API docs.
• We are using check-dts to test types with special unit tests.
• We keep types in separate files for better readability.
• With the new structure and test system, we fixed many small issues in types.

Other Changes

• Fixed calling replaceWith with input replaced node (by @​josephkaptur).
• Reduce dependencies by replacing chalk to colorette.
• Added Declaration#value auto-conversion to string to prevent plugin’s bugs.
• Fixed building PostCSS with Rollup (by @​MapGrid) because of circular dependencies.
• Moved unknown source from counter to random IDs: <input css 9M4X8l>:10:6.
• Removed docs from the npm package.

v7.0.39

Compare Source

• Reduce package size.
• Backport nanocolors to picocolors migration.

v7.0.38

Compare Source

• Update Processor#version.

v7.0.37

Compare Source

• Backport chalk to nanocolors migration.