Unity Linux 20.1060a Security Update: kernel (UTSA-2026-016780)

high Nessus Plugin ID 313423

Synopsis

The Unity Linux host is missing one or more security updates.

Description

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-016780 advisory.

In the Linux kernel, the following vulnerability has been resolved:

net_sched: drr: Fix double list add in class with netem as child qdisc

As described in Gerrard's report [1], there are use cases where a netem child qdisc will make the parent qdisc's enqueue callback reentrant.
In the case of drr, there won't be a UAF, but the code will add the same classifier to the list twice, which will cause memory corruption.

In addition to checking for qlen being zero, this patch checks whether the class was already added to the active_list (cl_is_active) before adding to the list to cover for the reentrant case.

[1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/

Tenable has extracted the preceding description block directly from the Unity Linux 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

Update the affected kernel package.

See Also

http://www.nessus.org/u?cfa70bd2

http://www.nessus.org/u?84f06998

https://nvd.nist.gov/vuln/detail/CVE-2025-37915

Plugin Details

Severity: High

ID: 313423

File Name: unity_linux_UTSA-2026-016780.nasl

Version: 1.1

Type: Local

Published: 5/8/2026

Updated: 5/8/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Medium

Base Score: 6

Temporal Score: 4.4

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

CVSS Score Source: CVE-2025-37915

CVSS v3

Risk Factor: High

Base Score: 7

Temporal Score: 6.1

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

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

Vulnerability Information

Required KB Items: Host/local_checks_enabled, Host/UOS-Server/release, Host/UOS-Server/rpm-list, Host/cpu

Exploit Ease: No known exploits are available

Patch Publication Date: 5/9/2026

Vulnerability Publication Date: 5/20/2025

Reference Information

CVE: CVE-2025-37915