Unity Linux 20.1050e Security Update: kernel (UTSA-2026-102043)

medium Nessus Plugin ID 338516

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-2026-102043 advisory.

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

module: Fix kernel panic when a symbol st_shndx is out of bounds

The module loader doesn't check for bounds of the ELF section index in simplify_symbols():

for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) { const char *name = info->strtab + sym[i].st_name;

switch (sym[i].st_shndx) { case SHN_COMMON:

[...]

default:
/* Divert to percpu allocation if a percpu var. */ if (sym[i].st_shndx == info->index.pcpu) secbase = (unsigned long)mod_percpu(mod);
else /** HERE --> **/ secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
sym[i].st_value += secbase;
break;
} }

A symbol with an out-of-bounds st_shndx value, for example 0xffff (known as SHN_XINDEX or SHN_HIRESERVE), may cause a kernel panic:

BUG: unable to handle page fault for address: ...
RIP: 0010:simplify_symbols+0x2b2/0x480 ...
Kernel panic - not syncing: Fatal exception

This can happen when module ELF is legitimately using SHN_XINDEX or when it is corrupted.

Add a bounds check in simplify_symbols() to validate that st_shndx is within the valid range before using it.

This issue was discovered due to a bug in llvm-objcopy, see relevant discussion for details [1].

[1] https://lore.kernel.org/linux-modules/[email protected]/

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: Medium

ID: 338516

File Name: unity_linux_UTSA-2026-102043.nasl

Version: 1.1

Type: Local

Family: Unity Linux Local Security Checks

Published: 8/21/2026

Updated: 8/21/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.76

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

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

CVSS Score Source: CVE-2026-31521

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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: 8/17/2026

Vulnerability Publication Date: 4/22/2026

Reference Information

CVE: CVE-2026-31521

Detections

Analytics