CVE-2026-40253
6.8 · MEDIUMOverview
CVE-2026-40253 is a medium-severity vulnerability affecting opencryptoki_project opencryptoki. It was published on April 16, 2026 and has a CVSS 3.1 base score of 6.8 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 6.8, rated MEDIUM. It requires local or adjacent network access to exploit. No authentication or special privileges are required for exploitation.
Technical 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 ed378f463ef73364c89feb0fc923f4dc867332
Remediation
Check the references section for vendor advisories and patches from opencryptoki_project. Update opencryptoki to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| opencryptoki_project | opencryptoki | 0 | Affected |
Frequently Asked Questions
What is CVE-2026-40253?
CVE-2026-40253 is a medium-severity vulnerability affecting opencryptoki_project opencryptoki. It was published on April 16, 2026 and has a CVSS 3.1 base score of 6.8 (MEDIUM).
How severe is CVE-2026-40253?
This vulnerability has a CVSS 3.1 base score of 6.8, rated MEDIUM. It requires local or adjacent network access to exploit. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-40253?
Check the references section for vendor advisories and patches from opencryptoki_project. Update opencryptoki to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-40253?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-40253 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
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