Linux Distros Unpatched Vulnerability : CVE-2026-87853

high Nessus Plugin ID 344337

Language:

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.

- A flaw was found in SSSD's IdP authentication provider. The eval_access_token_buf() function compares the OIDC subject identifier using strncmp() with the authenticated user's identifier length, performing a prefix comparison instead of an exact match. An attacker whose IdP identifier is a strict prefix of a target user's identifier can authenticate as the target user. (CVE-2026-87853)

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: High

ID: 344337

File Name: unpatched_CVE_2026_87853.nasl

Version: 1.5

Type: Local

Agent: unix

Family: Misc.

Published: 9/9/2026

Updated: 9/11/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.19

CVSS v2

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.7

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

CVSS Score Source: CVE-2026-87853

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.9

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

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

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:16.04:-:lts, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, cpe:/o:canonical:ubuntu_linux:26.04:-:lts, cpe:/o:debian:debian_linux:12.0, cpe:/o:debian:debian_linux:13.0, cpe:/o:redhat:enterprise_linux:10, p-cpe:/a:canonical:ubuntu_linux:sssd, p-cpe:/a:debian:debian_linux:sssd, p-cpe:/a:redhat:enterprise_linux:libipa_hbac, p-cpe:/a:redhat:enterprise_linux:libsss_autofs, p-cpe:/a:redhat:enterprise_linux:libsss_certmap, p-cpe:/a:redhat:enterprise_linux:libsss_idmap, p-cpe:/a:redhat:enterprise_linux:libsss_nss_idmap-devel, p-cpe:/a:redhat:enterprise_linux:libsss_nss_idmap, p-cpe:/a:redhat:enterprise_linux:libsss_sudo, p-cpe:/a:redhat:enterprise_linux:python3-libipa_hbac, p-cpe:/a:redhat:enterprise_linux:python3-libsss_nss_idmap, p-cpe:/a:redhat:enterprise_linux:python3-sss-murmur, p-cpe:/a:redhat:enterprise_linux:python3-sss, p-cpe:/a:redhat:enterprise_linux:python3-sssdconfig, p-cpe:/a:redhat:enterprise_linux:sssd-ad, p-cpe:/a:redhat:enterprise_linux:sssd-client, p-cpe:/a:redhat:enterprise_linux:sssd-common-pac, p-cpe:/a:redhat:enterprise_linux:sssd-common, p-cpe:/a:redhat:enterprise_linux:sssd-dbus, p-cpe:/a:redhat:enterprise_linux:sssd-idp, p-cpe:/a:redhat:enterprise_linux:sssd-ipa, p-cpe:/a:redhat:enterprise_linux:sssd-kcm, p-cpe:/a:redhat:enterprise_linux:sssd-krb5-common, p-cpe:/a:redhat:enterprise_linux:sssd-krb5, p-cpe:/a:redhat:enterprise_linux:sssd-ldap, p-cpe:/a:redhat:enterprise_linux:sssd-nfs-idmap, p-cpe:/a:redhat:enterprise_linux:sssd-passkey, p-cpe:/a:redhat:enterprise_linux:sssd-proxy, p-cpe:/a:redhat:enterprise_linux:sssd-tools, p-cpe:/a:redhat:enterprise_linux:sssd-winbind-idmap, p-cpe:/a:redhat:enterprise_linux:sssd

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

Exploit Ease: No known exploits are available

Reference Information

CVE: CVE-2026-87853

Detections

Analytics