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libexpat EUVDEUVD-2026-54990

| CVE-2026-72522 MEDIUM
Out-of-bounds Read (CWE-125)
2026-08-10 mitre GHSA-v867-w97p-3vx2
Information Disclosure Buffer Overflow Denial Of Service Libexpat Red Hat Suse
6.2
CVSS 3.1 · Vendor: mitre
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Severity by source

Vendor (mitre) PRIMARY
6.2 MEDIUM
AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
vuln.today AI
5.9 MEDIUM

AV:N reflects browser and network XML parsing exposure; AC:H captures the mandatory non-default compile-time 16-bit Unicode flag; no authentication or interaction required.

3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
4.0 AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
SUSE
7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Red Hat
6.2 MEDIUM
qualitative

Primary rating from Vendor (mitre).

CVSS VectorVendor: mitre

Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Lifecycle Timeline

4
Patch available
Aug 10, 2026 - 05:01 EUVD
Source Code Evidence Fetched
Aug 10, 2026 - 03:58 vuln.today
Analysis Generated
Aug 10, 2026 - 03:58 vuln.today
CVE Published
Aug 10, 2026 - 03:28 cve.org
MEDIUM 6.2

DescriptionCVE.org

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.

AnalysisAI

Infinite-loop denial-of-service in libexpat before 2.8.3 allows attackers supplying crafted UTF-16 XML to hang the parsing process indefinitely via a low Unicode surrogate handled as a high surrogate in the *_toUtf16 functions. The flaw is gated by a compile-time prerequisite - only builds configured with XML_UNICODE and XML_UNICODE_WCHAR_T are vulnerable - which specifically includes Firefox and Windows-native builds of applications embedding libexpat. …

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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

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Vulnerability AssessmentAI

Exploitation Exploitation requires libexpat to be compiled with both XML_UNICODE and XML_UNICODE_WCHAR_T compile-time flags, enabling 16-bit wide-character (UTF-16) output mode. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment Two CVSS vectors exist for this CVE and they conflict materially: NVD assigned AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (score 6.2), while the vendor's own patch changelog explicitly documents AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (score 7.5) - the AV:L assignment appears to be an NVD error, since Firefox parsing attacker-supplied web XML represents a clear network attack vector. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario Full exploit scenario with step-by-step reproduction available after sign-in.
Remediation Upgrade libexpat to version 2.8.3 or later, which incorporates the fix from PR #1296 (https://github.com/libexpat/libexpat/pull/1296). … Detailed patch versions, workarounds, and compensating controls in full report.
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Same weakness CWE-125 – Out-of-bounds Read

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Same technique Information Disclosure

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Vendor StatusVendor

SUSE

Severity: Important
Product Status
SLES15-SP5-CHOST-BYOS-SAP-CCloud Not-Affected
SLES15-SP5-CHOST-BYOS-SAP-CCloud Not-Affected
SLES15-SP6-CHOST-BYOS Not-Affected
SLES15-SP6-CHOST-BYOS-Aliyun Not-Affected
SLES15-SP6-CHOST-BYOS-Azure Not-Affected

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EUVD-2026-54990 vulnerability details – vuln.today
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