Debian dsa-6493 : libevent-2.1-7t64 - security update

critical Nessus Plugin ID 344780

Synopsis

The remote Debian host is missing one or more security-related updates.

Description

The remote Debian 13 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-6493 advisory.

- ------------------------------------------------------------------------- Debian Security Advisory DSA-6493-1 [email protected] https://www.debian.org/security/ Aron Xu September 11, 2026 https://www.debian.org/security/faq
- -------------------------------------------------------------------------

Package : libevent CVE ID : CVE-2026-63379 CVE-2026-63381 CVE-2026-63382 CVE-2026-63383 CVE-2026-63384 CVE-2026-63385 CVE-2026-63387 CVE-2026-63388

Several vulnerabilities were discovered in libevent, an asynchronous event notification library.

The HTTP implementation (evhttp) handled Transfer-Encoding and Content-Length headers, chunked-encoding line terminators, header line folding and chunked trailers too permissively, which could allow HTTP request smuggling, header injection or access control bypass when a libevent-based server or client is combined with an HTTP proxy.

Out-of-bounds memory accesses in the DNS (evdns), tagged RPC (evtag/evrpc) and buffered socket (bufferevent) code, and a use-after-free in evbuffer, could result in denial of service or potentially the execution of arbitrary code when processing untrusted input.

For the stable distribution (trixie), these problems have been fixed in version 2.1.13-stable-1~deb13u1.

We recommend that you upgrade your libevent packages.

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

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 these issues but has instead relied only on the application's self-reported version number.

Solution

Upgrade the libevent-2.1-7t64 packages.

Plugin Details

Severity: Critical

ID: 344780

File Name: debian_DSA-6493.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Debian Local Security Checks

Published: 9/11/2026

Updated: 9/11/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

Percentile: 96.31

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.3

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

CVSS Score Source: CVE-2026-63388

CVSS v3

Risk Factor: High

Base Score: 8.4

Temporal Score: 7.3

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

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

CVSS v4

Risk Factor: Critical

Base Score: 9.2

Threat Score: 7.1

Threat Vector: CVSS:4.0/E:U

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

CVSS Score Source: CVE-2026-63385

Vulnerability Information

CPE: cpe:/o:debian:debian_linux:13.0, p-cpe:/a:debian:debian_linux:libevent-2.1-7t64, p-cpe:/a:debian:debian_linux:libevent-core-2.1-7t64, p-cpe:/a:debian:debian_linux:libevent-dev, p-cpe:/a:debian:debian_linux:libevent-extra-2.1-7t64, p-cpe:/a:debian:debian_linux:libevent-openssl-2.1-7t64, p-cpe:/a:debian:debian_linux:libevent-pthreads-2.1-7t64

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

Exploit Ease: No known exploits are available

Patch Publication Date: 9/11/2026

Vulnerability Publication Date: 8/20/2026

Reference Information

CVE: CVE-2026-63379, CVE-2026-63381, CVE-2026-63382, CVE-2026-63383, CVE-2026-63384, CVE-2026-63385, CVE-2026-63387, CVE-2026-63388

Detections

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