Debian dsa-6291 : haproxy - security update

medium Nessus Plugin ID 316552

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-6291 advisory.

- ------------------------------------------------------------------------- Debian Security Advisory DSA-6291-1 [email protected] https://www.debian.org/security/ Salvatore Bonaccorso May 22, 2026 https://www.debian.org/security/faq
- -------------------------------------------------------------------------

Package : haproxy CVE ID : CVE-2026-33555

Martino Spagnuolo reported that the HTTP/3 parsing code in HAProxy, a fast and reliable load balancing reverse proxy, does not properly validate the received body size and the announced content-length header, which may result in HTTP request smuggling.

For the stable distribution (trixie), this problem has been fixed in version 3.0.11-1+deb13u3.

We recommend that you upgrade your haproxy packages.

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

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 haproxy packages.

Plugin Details

Severity: Medium

ID: 316552

File Name: debian_DSA-6291.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Debian Local Security Checks

Published: 5/25/2026

Updated: 5/25/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 2.4

CVSS v2

Risk Factor: Low

Base Score: 2.6

Temporal Score: 1.9

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

CVSS Score Source: CVE-2026-33555

CVSS v3

Risk Factor: Medium

Base Score: 4

Temporal Score: 3.5

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

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

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:haproxy-doc, p-cpe:/a:debian:debian_linux:vim-haproxy, cpe:/o:debian:debian_linux:13.0, p-cpe:/a:debian:debian_linux:haproxy

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

Exploit Ease: No known exploits are available

Patch Publication Date: 5/22/2026

Vulnerability Publication Date: 4/13/2026

Reference Information

CVE: CVE-2026-33555

IAVB: 2026-B-0103

Detections

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