Linux Distros Unpatched Vulnerability : CVE-2026-22796

medium Nessus Plugin ID 296900

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.

- Issue summary: A type confusion vulnerability exists in the signature verification of signed PKCS#7 data where an ASN1_TYPE union member is accessed without first validating the type, causing an invalid or NULL pointer dereference when processing malformed PKCS#7 data. Impact summary: An application performing signature verification of PKCS#7 data or calling directly the PKCS7_digest_from_attributes() function can be caused to dereference an invalid or NULL pointer when reading, resulting in a Denial of Service. The function PKCS7_digest_from_attributes() accesses the message digest attribute value without validating its type. When the type is not V_ASN1_OCTET_STRING, this results in accessing invalid memory through the ASN1_TYPE union, causing a crash. Exploiting this vulnerability requires an attacker to provide a malformed signed PKCS#7 to an application that verifies it. The impact of the exploit is just a Denial of Service, the PKCS7 API is legacy and applications should be using the CMS API instead. For these reasons the issue was assessed as Low severity. The FIPS modules in 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the PKCS#7 parsing implementation is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0, 1.1.1 and 1.0.2 are vulnerable to this issue. (CVE-2026-22796)

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

Solution

There is no known solution at this time.

Plugin Details

Severity: Medium

ID: 296900

File Name: unpatched_CVE_2026_22796.nasl

Version: 1.2

Type: local

Agent: unix

Family: Misc.

Published: 1/27/2026

Updated: 1/27/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 4.3

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

CVSS Score Source: CVE-2026-22796

CVSS v3

Risk Factor: Medium

Base Score: 5.3

Temporal Score: 4.9

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

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

Vulnerability Information

CPE: p-cpe:/a:centos:centos:openssl, cpe:/o:debian:debian_linux:11.0, p-cpe:/a:redhat:enterprise_linux:mokutil, p-cpe:/a:redhat:enterprise_linux:openssl-devel, p-cpe:/a:centos:centos:edk2-tools-doc, p-cpe:/a:centos:centos:ovmf, cpe:/o:redhat:enterprise_linux:6, p-cpe:/a:redhat:enterprise_linux:mingw64-openssl, p-cpe:/a:redhat:enterprise_linux:edk2-tools, p-cpe:/a:redhat:enterprise_linux:shim-unsigned-x64, p-cpe:/a:centos:centos:compat-openssl10, p-cpe:/a:redhat:enterprise_linux:openssl-perl, p-cpe:/a:centos:centos:aavmf, p-cpe:/a:centos:centos:openssl-libs, p-cpe:/a:centos:centos:openssl-perl, p-cpe:/a:redhat:enterprise_linux:openssl-static, cpe:/o:redhat:enterprise_linux:9, p-cpe:/a:redhat:enterprise_linux:edk2-tools-doc, p-cpe:/a:redhat:enterprise_linux:aavmf, p-cpe:/a:centos:centos:shim-unsigned-x64, p-cpe:/a:centos:centos:openssl-static, cpe:/o:centos:centos:8, p-cpe:/a:centos:centos:edk2, p-cpe:/a:redhat:enterprise_linux:shim-ia32, p-cpe:/a:centos:centos:edk2-ovmf, p-cpe:/a:redhat:enterprise_linux:compat-openssl10, p-cpe:/a:redhat:enterprise_linux:compat-openssl11, p-cpe:/a:redhat:enterprise_linux:edk2, cpe:/o:redhat:enterprise_linux:8, cpe:/o:redhat:enterprise_linux:10, p-cpe:/a:redhat:enterprise_linux:openssl-libs, p-cpe:/a:redhat:enterprise_linux:shim-x64, p-cpe:/a:centos:centos:shim-x64, p-cpe:/a:centos:centos:mokutil, p-cpe:/a:centos:centos:mingw64-openssl, p-cpe:/a:redhat:enterprise_linux:shim-unsigned-aarch64, p-cpe:/a:centos:centos:openssl-devel, p-cpe:/a:centos:centos:shim-ia32, p-cpe:/a:redhat:enterprise_linux:shim-aa64, p-cpe:/a:redhat:enterprise_linux:mingw32-openssl, p-cpe:/a:debian:debian_linux:openssl, cpe:/o:centos:centos:7, p-cpe:/a:centos:centos:compat-openssl11, p-cpe:/a:centos:centos:shim-aa64, p-cpe:/a:centos:centos:edk2-tools, cpe:/o:redhat:enterprise_linux:7, p-cpe:/a:redhat:enterprise_linux:edk2-ovmf, p-cpe:/a:centos:centos:mingw32-openssl, p-cpe:/a:redhat:enterprise_linux:shim, p-cpe:/a:redhat:enterprise_linux:openssl, p-cpe:/a:centos:centos:shim-unsigned-aarch64, p-cpe:/a:redhat:enterprise_linux:ovmf, cpe:/o:debian:debian_linux:14.0, p-cpe:/a:centos:centos:edk2-aarch64, p-cpe:/a:centos:centos:shim, p-cpe:/a:redhat:enterprise_linux:edk2-aarch64

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

Exploit Ease: No known exploits are available

Reference Information

CVE: CVE-2026-22796

Detections

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