CVE-2026-40253
Publication date 16 April 2026
Last updated 1 September 2026
Ubuntu priority
Medium
Description
openCryptoki is a PKCS#11 library and provides tooling for Linux and AIX. In versions 3.26.0 and below, the BER/DER decoding functions in the shared common library (asn1.c) accept a raw pointer but no buffer length parameter, and trust attacker-controlled BER length fields without validating them against actual buffer boundaries. All primitive decoders are affected: ber_decode_INTEGER, ber_decode_SEQUENCE, ber_decode_OCTET_STRING, ber_decode_BIT_STRING, and ber_decode_CHOICE. Additionally, ber_decode_INTEGER can produce integer underflows when the encoded length is zero. An attacker supplying a malformed BER-encoded cryptographic object through PKCS#11 operations such as C_CreateObject or C_UnwrapKey, token loading from disk, or remote backend communication can trigger out-of-bounds reads. This affects all token backends (Soft, ICA, CCA, TPM, EP11, ICSF) since the vulnerable code is in the shared common library. A patch is available thorugh commit ed378f463ef73364c89feb0fc923f4dc867332a3.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| opencryptoki | 26.04 LTS resolute |
Fixed 3.26.0+dfsg-0ubuntu1.1
|
| 25.10 questing | Ignored end of life, was needs-triage | |
| 24.04 LTS noble |
Fixed 3.23.0+dfsg-0ubuntu3.1
|
|
| 22.04 LTS jammy |
Fixed 3.17.0+dfsg+20220202.b40982e-0ubuntu1.3
|
|
| 20.04 LTS focal |
Vulnerable
|
|
| 18.04 LTS bionic |
Vulnerable
|
|
| 16.04 LTS xenial |
Vulnerable
|
Severity score breakdown
CVSS version: CVSS v3.0
Base score 6.8 · Medium
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
References
Related Ubuntu Security Notices (USN)
- USN-8686-1
- openCryptoki vulnerabilities
- 27 August 2026
- USN-8707-1
- openCryptoki vulnerabilities
- 31 August 2026