Linux Distros Unpatched Vulnerability : CVE-2026-98490

critical Nessus Plugin ID 367058

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.

- net: openvswitch: conntrack: fix helper UAF due to extensions realloc While calling the helpers, a raw pointer to the extensions area is wired into expectations list: -> nf_ct_helper() -> helper->help() -> nf_ct_expect_related_report() -> nf_ct_expect_insert() -> hlist_add_head_rcu(&exp->lnode, &master_help->expectations) In case the connection is not confirmed yet, more extensions can be added afterwards with *_ext_add() calls reallocating the extension space and leaving the now invalid pointer in the expectations list that is later accessed while removing the expectation. Make sure that helpers are called at the end after all the other extensions are already added. Note that the helper rejection now leaves the mark and labels set, but that's not different from how the NAT was handled before or how the mark and the labels were handled on confirmation failure. And there are no atomicity guarantees provided by the API anyway. (CVE-2026-98490)

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-2026-98490

Plugin Details

Severity: Critical

ID: 367058

File Name: unpatched_CVE_2026_98490.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Misc.

Published: 10/18/2026

Updated: 10/18/2026

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

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.42

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.4

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

CVSS Score Source: CVE-2026-98490

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 9

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

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

Vulnerability Information

CPE: cpe:/o:debian:debian_linux:12.0, p-cpe:/a:debian:debian_linux:linux

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: 10/18/2026

Reference Information

CVE: CVE-2026-98490