Linux Distros Unpatched Vulnerability : CVE-2026-78661

medium Nessus Plugin ID 373000

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

- When coalescing adjacent text nodes in addText and fosterParent, appending to an existing TextNode's Data via string concatenation (n.Data += text) reallocated and copied the accumulated string on every token.
Inputs containing many short text runs separated by ignored end tags (such as a</x>) caused O(n^2) allocations and byte copies. Accumulate coalesced text in per-node byte slices during parsing and materialize Data strings once at the end of parse. (CVE-2026-78661)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

See Also

https://security-tracker.debian.org/tracker/CVE-2026-78661

https://ubuntu.com/security/CVE-2026-78661

Plugin Details

Severity: Medium

ID: 373000

File Name: unpatched_CVE_2026_78661.nasl

Version: 1.2

Type: Local

Agent: unix

Family: Misc.

Published: 10/28/2026

Updated: 10/28/2026

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

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.72

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:14.04:-:lts, cpe:/o:canonical:ubuntu_linux:16.04:-:lts, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, cpe:/o:canonical:ubuntu_linux:26.04:-:lts, cpe:/o:canonical:ubuntu_linux:26.10, cpe:/o:debian:debian_linux:12.0, cpe:/o:debian:debian_linux:13.0, cpe:/o:debian:debian_linux:14.0, p-cpe:/a:canonical:ubuntu_linux:adsys, p-cpe:/a:canonical:ubuntu_linux:containerd, p-cpe:/a:canonical:ubuntu_linux:golang-1.10, p-cpe:/a:canonical:ubuntu_linux:golang-1.13, p-cpe:/a:canonical:ubuntu_linux:golang-1.14, p-cpe:/a:canonical:ubuntu_linux:golang-1.16, p-cpe:/a:canonical:ubuntu_linux:golang-1.17, p-cpe:/a:canonical:ubuntu_linux:golang-1.18, p-cpe:/a:canonical:ubuntu_linux:golang-1.20, p-cpe:/a:canonical:ubuntu_linux:golang-1.21, p-cpe:/a:canonical:ubuntu_linux:golang-1.22, p-cpe:/a:canonical:ubuntu_linux:golang-1.23, p-cpe:/a:canonical:ubuntu_linux:golang-1.24, p-cpe:/a:canonical:ubuntu_linux:golang-1.25, p-cpe:/a:canonical:ubuntu_linux:golang-1.26, p-cpe:/a:canonical:ubuntu_linux:golang-1.27, p-cpe:/a:canonical:ubuntu_linux:golang-1.6, p-cpe:/a:canonical:ubuntu_linux:golang-1.8, p-cpe:/a:canonical:ubuntu_linux:golang-1.9, p-cpe:/a:canonical:ubuntu_linux:golang-golang-x-net-dev, p-cpe:/a:canonical:ubuntu_linux:golang-golang-x-net, p-cpe:/a:canonical:ubuntu_linux:google-guest-agent, p-cpe:/a:canonical:ubuntu_linux:google-osconfig-agent, p-cpe:/a:canonical:ubuntu_linux:juju-core, p-cpe:/a:canonical:ubuntu_linux:lxd, p-cpe:/a:debian:debian_linux:golang-golang-x-net

Required KB Items: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 10/27/2026

Reference Information

CVE: CVE-2026-78661