CVE-2026-40253

MEDIUM EPSS 5.6%
Published Apr 16, 20262mo ago · Modified Jun 17, 20261w ago
6.1 CVSS 3.1
Medium
Find Similar
Published Apr 16, 2026 2mo ago
Last Modified Jun 17, 2026 1w ago

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.

CVSS Details

Base Score
6.1
Exploitability
1.8
Impact
4.2
Vector string
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required None
User Interaction Required
Scope Unchanged
Confidentiality Low
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
5.6% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-125 Out-of-bounds Read Memory Safety

Affected Products 1

VendorProductVersionRange
opencryptoki_projectopencryptoki* ≤3.26.0

References 2

  • github.com https://github.com/opencryptoki/opencryptoki/commit/ed378f463ef73364c89feb0fc923f4dc867332a3
    Patch
  • github.com https://github.com/opencryptoki/opencryptoki/security/advisories/GHSA-c9cf-6vr4-wfxm
    ExploitMitigationPatchVendor Advisory

Remediation

  • github.com https://github.com/opencryptoki/opencryptoki/commit/ed378f463ef73364c89feb0fc923f4dc867332a3
    Patch
  • github.com https://github.com/opencryptoki/opencryptoki/security/advisories/GHSA-c9cf-6vr4-wfxm
    ExploitMitigationPatchVendor Advisory