Detections
Analytics

Ubuntu 26.04 LTS : OpenSSL vulnerabilities (USN-8861-1)

high Nessus Plugin ID 362522

Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

The remote Ubuntu 26.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8861-1 advisory.

 It was discovered that OpenSSL had an inefficient algorithm in its QUIC stream reassembly implementation.
 A remote attacker could possibly use this issue to cause OpenSSL to use excessive CPU resources, leading to a denial of service. (CVE-2026-42772)

 It was discovered that OpenSSL did not properly limit memory allocated for QUIC packet buffers. A remote attacker could possibly use this issue to cause OpenSSL to use excessive memory resources, leading to a denial of service. (CVE-2026-54873)

Tenable has extracted the preceding description block directly from the Ubuntu 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

Update the affected libssl3t64, openssl and / or openssl-provider-legacy packages.

See Also

https://ubuntu.com/security/notices/USN-8861-1

Plugin Details

Severity: High

ID: 362522

File Name: ubuntu_USN-8861-1.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 10/2/2026

Updated: 10/2/2026

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

Risk Information

VPR

Risk Factor: Medium

Score: 5.7

Percentile: 95.88

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-2026-54873

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:libssl3t64, p-cpe:/a:canonical:ubuntu_linux:openssl-provider-legacy, p-cpe:/a:canonical:ubuntu_linux:openssl

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

Exploit Ease: No known exploits are available

Patch Publication Date: 10/1/2026

Vulnerability Publication Date: 9/29/2026

Reference Information

CVE: CVE-2026-42772, CVE-2026-54873

IAVA: 2026-A-1072

USN: 8861-1