Linux Distros Unpatched Vulnerability : CVE-2026-102631

medium Nessus Plugin ID 366805

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.

- In authd before 0.7.1, the user identity matching in UpdateUser (internal/users/manager.go) resolves an incoming login by the broker-scoped provider ID, but falls back to matching the username when the provider ID does not belong to any known user, and does not reject a conflicting non-empty provider ID. If an identity provider reassigns an email address, which authd uses as the username, to a new account, the new account inherits the previous user's local UID and home directory on its next login. This allows the new user to access and modify files belonging to the previous user, including credentials such as SSH keys and cloud API tokens, and silently rebinds the local account record to the new identity. As a mitigation, administrators should lock or delete the previous user's local authd account when the corresponding IdP account is removed. (CVE-2026-102631)

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://ubuntu.com/security/CVE-2026-102631

Plugin Details

Severity: Medium

ID: 366805

File Name: unpatched_CVE_2026_102631.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Misc.

Published: 10/17/2026

Updated: 10/17/2026

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: 4.3

Percentile: 53.47

CVSS v2

Risk Factor: Low

Base Score: 3.6

Temporal Score: 3.1

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

CVSS Score Source: CVE-2026-102631

CVSS v3

Risk Factor: High

Base Score: 7.1

Temporal Score: 6.5

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

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

CVSS v4

Risk Factor: Medium

Base Score: 5.9

Threat Score: 2.1

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:26.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:authd

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: 10/15/2026

Reference Information

CVE: CVE-2026-102631