CVE-2026-40253 (GCVE-0-2026-40253)
Vulnerability from cvelistv5 – Published: 2026-04-16 22:04 – Updated: 2026-04-16 22:04
VLAI?
Title
openCryptoki: Memory safety vulnerabilities in BER/DER decoders in asn1.c
Summary
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.
Severity ?
6.8 (Medium)
CWE
- CWE-125 - Out-of-bounds Read
Assigner
References
| URL | Tags | |||||||
|---|---|---|---|---|---|---|---|---|
|
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Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| opencryptoki | opencryptoki |
Affected:
<= 3.26.0
|
{
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"product": "opencryptoki",
"vendor": "opencryptoki",
"versions": [
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}
],
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"baseScore": 6.8,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H",
"version": "3.1"
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"shortName": "GitHub_M"
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"tags": [
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},
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"discovery": "UNKNOWN"
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"title": "openCryptoki: Memory safety vulnerabilities in BER/DER decoders in asn1.c"
}
},
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"datePublished": "2026-04-16T22:04:44.005Z",
"dateReserved": "2026-04-10T17:31:45.786Z",
"dateUpdated": "2026-04-16T22:04:44.005Z",
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}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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