Unity Linux 20.1050e Security Update: kernel (UTSA-2026-099954)

high Nessus Plugin ID 336865

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-2026-099954 advisory.

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

dm: fix a buffer overflow in ioctl processing

Tony Asleson (using Claude) found a buffer overflow in dm-ioctl in the function retrieve_status:

1. The code in retrieve_status checks that the output string fits into the output buffer and writes the output string there 2. Then, the code aligns the outptr variable to the next 8-byte boundary:
outptr = align_ptr(outptr);
3. The alignment doesn't check overflow, so outptr could point past the buffer end 4. The for loop is iterated again, it executes:
remaining = len - (outptr - outbuf);
5. If outptr points past outbuf + len, the arithmetics wraps around and the variable remaining contains unusually high number 6. With remaining being high, the code writes more data past the end of the buffer

Luckily, this bug has no security implications because:
1. Only root can issue device mapper ioctls 2. The commonly used libraries that communicate with device mapper (libdevmapper and devicemapper-rs) use buffer size that is aligned to 8 bytes - thus, outptr = align_ptr(outptr) can't overshoot the input buffer and the bug can't happen accidentally

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.

Plugin Details

Severity: High

ID: 336865

File Name: unity_linux_UTSA-2026-099954.nasl

Version: 1.1

Type: Local

Family: Unity Linux Local Security Checks

Published: 8/17/2026

Updated: 8/17/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.14

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-2026-46294

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/AC:L/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/cpu, Host/UOS-Server/release, Host/UOS-Server/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 8/13/2026

Vulnerability Publication Date: 6/8/2026

Reference Information

CVE: CVE-2026-46294

Detections

Analytics