Unity Linux 20.1050a Security Update: kernel (UTSA-2026-098887)

high Nessus Plugin ID 340370

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-2026-098887 advisory.

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

net: ip_gre: require CAP_NET_ADMIN in the device netns for changelink

A tunnel changelink() operates on at most two netns, dev_net(dev) and the tunnel link netns t->net. They differ once the device is created in or moved to a netns other than the one the request runs in. The rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a caller privileged there but not in t->net can rewrite a tunnel that lives in t->net.

Add rtnl_dev_link_net_capable() next to rtnl_get_net_ns_capable() in net/core/rtnetlink.c. It requires CAP_NET_ADMIN in the link netns and is skipped when the link netns is dev_net(dev), where the rtnl path already checked it. The other patches in this series use the same helper.

Gate ipgre_changelink() and erspan_changelink() with it, at the top of the op before any attribute is parsed, because the parsers update live tunnel fields first. ipgre_netlink_parms() sets t->collect_md before ip_tunnel_changelink() runs.

Commit 8b484efd5cb4 (ip6: vti: Use ip6_tnl.net in vti6_siocdevprivate().) added the same check on the ioctl path. This adds it on RTM_NEWLINK.

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

https://nvd.nist.gov/vuln/detail/CVE-2026-63829

http://www.nessus.org/u?263e338b

http://www.nessus.org/u?5f5381d2

Plugin Details

Severity: High

ID: 340370

File Name: unity_linux_UTSA-2026-098887.nasl

Version: 1.1

Type: Local

Published: 8/26/2026

Updated: 8/26/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5

Percentile: 93.84

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

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

CVSS Score Source: CVE-2026-63829

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/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/cpu, Host/UOS-Server/release, Host/UOS-Server/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 8/10/2026

Vulnerability Publication Date: 7/8/2026

Reference Information

CVE: CVE-2026-63829