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Linux Distros Unpatched Vulnerability : CVE-2026-40253

medium Nessus Plugin ID 307346

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

 - 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. (CVE-2026-40253)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

See Also

https://access.redhat.com/security/cve/cve-2026-40253

Plugin Details

Severity: Medium

ID: 307346

File Name: unpatched_CVE_2026_40253.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Misc.

Published: 4/17/2026

Updated: 4/17/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.0

CVSS v2

Risk Factor: Medium

Base Score: 6.4

Temporal Score: 5.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:P

CVSS Score Source: CVE-2026-40253

CVSS v3

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 6.2

Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:U/RC:C

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:opencryptoki-ccatok, p-cpe:/a:centos:centos:opencryptoki-libs, cpe:/o:centos:centos:8, p-cpe:/a:centos:centos:opencryptoki-ccatok, p-cpe:/a:centos:centos:opencryptoki-icsftok, p-cpe:/a:centos:centos:opencryptoki-ep11tok, cpe:/o:centos:centos:7, p-cpe:/a:centos:centos:opencryptoki, cpe:/o:redhat:enterprise_linux:10, cpe:/o:redhat:enterprise_linux:8, p-cpe:/a:redhat:enterprise_linux:opencryptoki-icsftok, cpe:/o:redhat:enterprise_linux:9, p-cpe:/a:redhat:enterprise_linux:opencryptoki-swtok, p-cpe:/a:redhat:enterprise_linux:opencryptoki-libs, cpe:/o:redhat:enterprise_linux:7, p-cpe:/a:centos:centos:opencryptoki-swtok, p-cpe:/a:centos:centos:opencryptoki-tpmtok, p-cpe:/a:redhat:enterprise_linux:opencryptoki-icatok, p-cpe:/a:centos:centos:opencryptoki-devel, p-cpe:/a:redhat:enterprise_linux:opencryptoki-ep11tok, p-cpe:/a:redhat:enterprise_linux:opencryptoki-devel, p-cpe:/a:redhat:enterprise_linux:opencryptoki-tpmtok, p-cpe:/a:centos:centos:opencryptoki-icatok, p-cpe:/a:redhat:enterprise_linux:opencryptoki

Required KB Items: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 4/16/2026

Reference Information

CVE: CVE-2026-40253