Detections
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EulerOS 2.0 SP12 : expat (EulerOS-SA-2026-4402)

high Nessus Plugin ID 376736

Synopsis

The remote EulerOS host is missing multiple security updates.

Description

According to the versions of the expat packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

 Expat through 2.8.3 contains a denial of service vulnerability caused by quadratic algorithmic complexity in the storeAtts() function in xmlparse.c, where processing N specified attributes with non-normalized values triggers an O(N^2) linear scan of elementType-defaultAtts to determine CDATA status. A remote unauthenticated attacker can supply a single well-formed XML document of a few megabytes to an application parsing untrusted XML to cause excessive CPU consumption, resulting in denial of service without requiring authentication, external entity resolution, or non-default parser options.(CVE-2026-66046)

 Expat through 2.8.3 contains an out-of-bounds read vulnerability that allows attackers to trigger memory corruption by processing XML with external entity parsers created via XML_ExternalEntityParserCreate. A struct size mismatch between ELEMENT_TYPE members causes storeAtts to read the attIndex member past allocated memory boundaries, resulting in failure to normalize whitespace in non-CDATA attributes or a wild pointer dereference causing a segfault. This vulnerability was introduced by the fix for CVE-2026-66046.(CVE-2026-76641)

 libexpat before 2.8.3 has an out-of-bounds read and resultant infinite loop because low surrogates are treated the same as high surrogates during Unicode processing in the *_toUtf16 functions.(CVE-2026-72522)

 libexpat before 2.8.4 lacks handler call depth tracking with custom encoding callbacks. Thus, a use-after- free can occur. NOTE: this is similar to CVE-2026-50219, CVE-2026-56131 and CVE-2026-56412.(CVE-2026-76957)

Tenable has extracted the preceding description block directly from the EulerOS expat security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the affected expat packages.

See Also

http://www.nessus.org/u?ae2d0f46

Plugin Details

Severity: High

ID: 376736

File Name: EulerOS_SA-2026-4402.nasl

Version: 1.1

Type: Local

Published: 11/6/2026

Updated: 11/6/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.9

Percentile: 96.32

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5.3

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

CVSS Score Source: CVE-2026-76957

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7

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:P/RL:O/RC:C

CVSS v4

Risk Factor: High

Base Score: 8.7

Threat Score: 6.6

Threat Vector: CVSS:4.0/E:P

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS Score Source: CVE-2026-76641

Vulnerability Information

CPE: cpe:/o:huawei:euleros:2.0, p-cpe:/a:huawei:euleros:expat-devel, p-cpe:/a:huawei:euleros:expat-help, p-cpe:/a:huawei:euleros:expat

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/EulerOS/release, Host/EulerOS/rpm-list, Host/EulerOS/sp

Excluded KB Items: Host/EulerOS/uvp_version

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 11/5/2026

Vulnerability Publication Date: 8/10/2026

Reference Information

CVE: CVE-2026-66046, CVE-2026-72522, CVE-2026-76641, CVE-2026-76957

IAVA: 2026-A-0899-S, 2026-A-0925-S