CVE-2026-11979

HIGHNVD 7.87.8—
EchelonGraph scoreHIGH confidence

Score 7.8 from GitHub Security Advisory (severity: LOW) published 2026-06-29. NVD baseline CVSS 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 5 sources updated this week
7.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.8Exploit: NoneExposed: 0

A fix is available — apply it.

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.

CVSS v3
7.8
EG Score
7.8(high)
EPSS
4.4%
KEV
Not listed

Published

June 29, 2026

Last Modified

June 30, 2026

Advisory Details (2)

Auto-updated Jun 30, 2026
No patch confirmed yet.
generic

Client Challenge

https://gitlab.gnome.org/GNOME/libxml2/-/commit/c2e233fc1b341685fc99621b2768b503f777a72e
generic

Vulnerability in libxml2 software | CERT Polska

https://cert.pl/en/posts/2026/06/CVE-2026-11979

Vendor Advisories for CVE-2026-11979(3)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatlibxml2-main-2.15.3-0.1.1.hum12026-06-30redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 35× in last 7d / 37× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-06 20:25 UTCEG score recompute
  2. 2026-07-06 20:25 UTCVendor advisory
  3. 2026-07-06 20:25 UTCGHSA enrichment
  4. 2026-07-06 07:52 UTCEG score recompute
  5. 2026-07-06 07:52 UTCVendor advisory
  6. 2026-07-06 07:52 UTCGHSA enrichment
  7. 2026-07-06 02:23 UTCEPSS rescore
  8. 2026-07-05 19:23 UTCEG score recompute
  9. 2026-07-05 19:23 UTCVendor advisory
  10. 2026-07-05 19:23 UTCGHSA enrichment
  11. 2026-07-05 06:54 UTCEG score recompute
  12. 2026-07-05 06:54 UTCVendor advisory
  13. 2026-07-05 06:54 UTCGHSA enrichment
  14. 2026-07-05 02:30 UTCEPSS rescore
  15. 2026-07-05 02:30 UTCEPSS rescore
  16. 2026-07-04 18:25 UTCEG score recompute
  17. 2026-07-04 18:25 UTCVendor advisory
  18. 2026-07-04 18:25 UTCGHSA enrichment
  19. 2026-07-04 06:31 UTCEPSS rescore
  20. 2026-07-04 05:56 UTCEG score recompute
  21. 2026-07-04 05:56 UTCVendor advisory
  22. 2026-07-04 05:56 UTCGHSA enrichment
  23. 2026-07-03 17:26 UTCEG score recompute
  24. 2026-07-03 17:26 UTCVendor advisory
  25. 2026-07-03 17:26 UTCGHSA enrichment
Show 12 more
  1. 2026-07-03 04:58 UTCEG score recompute
  2. 2026-07-03 04:58 UTCVendor advisory
  3. 2026-07-03 04:58 UTCGHSA enrichment
  4. 2026-07-02 16:29 UTCEG score recompute▲ 6.00
  5. 2026-07-02 16:29 UTCVendor advisory
  6. 2026-07-02 16:29 UTCGHSA enrichment
  7. 2026-07-01 15:06 UTCEPSS rescore
  8. 2026-07-01 15:06 UTCEPSS rescore
  9. 2026-06-30 23:22 UTCEPSS rescore
  10. 2026-06-30 20:33 UTCNVD updateCVSS v3 → 7.8 · severity → HIGH
  11. 2026-06-29 13:33 UTCEG score recompute
  12. 2026-06-29 13:32 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-11979?
CVE-2026-11979 is a high vulnerability published on June 29, 2026. 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…
When was CVE-2026-11979 disclosed?
CVE-2026-11979 was first published in the National Vulnerability Database on June 29, 2026, with the most recent update on June 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-11979 actively exploited?
CVE-2026-11979 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 4.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-11979?
CVE-2026-11979 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-11979?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-11979, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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