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Ubuntu 26.04 LTS : c-ares vulnerability (USN-8844-1)

high Nessus Plugin ID 351470

Synopsis

The remote Ubuntu host is missing a security update.

Description

The remote Ubuntu 26.04 LTS host has packages installed that are affected by a vulnerability as referenced in the USN-8844-1 advisory.

 It was discovered that c-ares incorrectly handled certain query completion callbacks. An attacker could possibly use this issue to trigger a use- after-free or double-free, resulting in a denial of service or arbitrary code execution.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected libc-ares2 and / or libcares2 packages.

See Also

https://ubuntu.com/security/notices/USN-8844-1

Plugin Details

Severity: High

ID: 351470

File Name: ubuntu_USN-8844-1.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 9/30/2026

Updated: 9/30/2026

Supported Sensors: Continuous Assessment, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.63

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

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

CVSS Score Source: CVE-2026-33630

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

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

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:26.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:libc-ares2, p-cpe:/a:canonical:ubuntu_linux:libcares2

Required KB Items: Host/cpu, Host/Ubuntu, Host/Ubuntu/release, Host/Debian/dpkg-l

Exploit Ease: No known exploits are available

Patch Publication Date: 9/29/2026

Vulnerability Publication Date: 7/7/2026

Reference Information

CVE: CVE-2026-33630

USN: 8844-1