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🛡️ OESA-2026-3039 — libxml2 (CVE-2026-11979)

🟠 CVSS 8.0 — High ✅ No Known Exploit OSV
8.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

libxml2 security update

This library allows to manipulate XML files. It includes support to read, modify and write XML and HTML files. There is DTDs support this includes parsing and validation even with complex DtDs, either at parse time or later once the document has been modified. The output can be a simple SAX stream or and in-memory DOM like representations. In this case one can use the built-in XPath and XPointer implementation to select sub nodes or ranges. A flexible Input/Output mechanism is available, with existing HTTP and FTP modules and combined to an URI library.

Security Fix(es):

libxml2 is vulnerable to multiple stack-based buffer overflows in the xmlcatalog utility when running in --shell mode. The usershell() function processes user input using fixed-size stack buffers without proper bounds checking.

By supplying an overly long input line, an attacker can overflow internal buffers (command, arg, and argv) during input parsing. This results in memory corruption within the stack frame.

Successful exploitation may cause a crash or potentially allow arbitrary code execution in the context of the xmlcatalog process.

This issue has been fixed in the commit c2e233fc.

NOTE:

The maintainers of this project did not agree that this issue is a vulnerability and considered it a bug.(CVE-2026-11979)

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

  • Attack vector: Local — a local account, shell or session on the host is needed.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: None — an unauthenticated stranger can try it.
  • User interaction: Required — someone has to click, open or visit something.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: High — total loss, or loss the attacker controls.
  • Availability impact: High — total loss, or loss the attacker controls.

Affected software

OESA-2026-3039 is recorded against 1 package.

  • libxml2 (fixed in 2.9.10-58.oe2003sp4)

Timeline and source

Published on 19 July 2026 and last revised on 18 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

www.openeuler.org (Advisory)
nvd.nist.gov (Advisory)

Other advisories for this package

libxml2 has other advisories on record. If you are patching this one, these are worth checking on the same host:

Details

Severity HIGH
CVSS Score 8.0
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2026-07-19
Updated 2026-08-20
Modified 2026-08-18
Fix URL N/A

Affected Packages

Software From version Fixed in
libxml2 — 2.9.10-58.oe2003sp4

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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