Debian dsa-6446 : expat - security update

medium Nessus Plugin ID 337123

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Synopsis

The remote Debian host is missing a security-related update.

Description

The remote Debian 13 host has packages installed that are affected by a vulnerability as referenced in the dsa-6446 advisory.

- ------------------------------------------------------------------------- Debian Security Advisory DSA-6446-1 [email protected] https://www.debian.org/security/ Aron Xu August 18, 2026 https://www.debian.org/security/faq
- -------------------------------------------------------------------------

Package : expat CVE ID : CVE-2026-72522 Debian Bug : 1144064

A flaw was discovered in the UTF-16 decoding support of expat, an XML parsing C library, where low surrogates were treated in the same way as high surrogates. Parsing crafted XML input may result in an out-of-bounds read and a resultant infinite loop, leading to denial of service. Only builds with 16 bit character support are affected, which in Debian is the libexpatw library shipped in the libexpat1 package.

In addition, this update corrects a regression introduced in the previous security update (DSA-6404-1): on 32 bit architectures, documents larger than 2 GiB were incorrectly rejected with an out of memory error.

For the stable distribution (trixie), this problem has been fixed in version 2.8.3-1~deb13u1.

We recommend that you upgrade your expat packages.

For the detailed security status of expat please refer to its security tracker page at:
https://security-tracker.debian.org/tracker/expat

Further information about Debian Security Advisories, how to apply these updates to your system and frequently asked questions can be found at: https://www.debian.org/security/

Mailing list: [email protected]

Tenable has extracted the preceding description block directly from the Debian 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

Upgrade the expat packages.

Plugin Details

Severity: Medium

ID: 337123

File Name: debian_DSA-6446.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Debian Local Security Checks

Published: 8/18/2026

Updated: 8/18/2026

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

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.72

CVSS v2

Risk Factor: Medium

Base Score: 4.9

Temporal Score: 3.6

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

CVSS Score Source: CVE-2026-72522

CVSS v3

Risk Factor: Medium

Base Score: 6.2

Temporal Score: 5.4

Vector: CVSS:3.0/AV:L/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:debian:debian_linux:13.0, p-cpe:/a:debian:debian_linux:expat, p-cpe:/a:debian:debian_linux:libexpat1-dev, p-cpe:/a:debian:debian_linux:libexpat1-udeb, p-cpe:/a:debian:debian_linux:libexpat1

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

Exploit Ease: No known exploits are available

Patch Publication Date: 8/18/2026

Vulnerability Publication Date: 8/10/2026

Reference Information

CVE: CVE-2026-72522

Detections

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