CVE-2026-56411

MEDIUMPre-NVD 6.96.9—
EchelonGraph scoreHIGH confidence

Score 6.9 from GitHub Security Advisory published 2026-06-21. a secondary CVSS source baseline 6.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
6.9
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.9Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

xmlwf in libexpat before 2.8.2 has an integer overflow in endDoctypeDecl via NOTATION declarations.

CVSS v3
6.9
EG Score
6.9(high)
EPSS
1.5%
KEV
Not listed

Published

June 21, 2026

Last Modified

June 23, 2026

Advisory Details (1)

Auto-updated Jun 22, 2026
Upstream fix merged — awaiting tagged release. Sources: github_pr.
github_pr

[CVE-2026-56411] xmlwf: protect notation list allocation from integer overflow

Fix merged in libexpat/libexpat PR #1263 on 2026-06-03 — awaiting tagged release

https://github.com/libexpat/libexpat/pull/1263

Vendor Advisories for CVE-2026-56411(2)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 28× in last 7d / 52× 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 13:33 UTCEG score recompute
  2. 2026-07-06 13:33 UTCVendor advisory
  3. 2026-07-06 13:33 UTCGHSA enrichment
  4. 2026-07-06 02:23 UTCEPSS rescore
  5. 2026-07-06 02:23 UTCEPSS rescore
  6. 2026-07-05 12:06 UTCEG score recompute
  7. 2026-07-05 12:06 UTCVendor advisory
  8. 2026-07-05 12:06 UTCGHSA enrichment
  9. 2026-07-05 02:31 UTCEPSS rescore
  10. 2026-07-05 02:30 UTCEPSS rescore
  11. 2026-07-04 10:47 UTCEG score recompute
  12. 2026-07-04 10:47 UTCVendor advisory
  13. 2026-07-04 10:47 UTCGHSA enrichment
  14. 2026-07-04 06:31 UTCEPSS rescore
  15. 2026-07-04 06:31 UTCEPSS rescore
  16. 2026-07-03 09:25 UTCEG score recompute
  17. 2026-07-03 09:25 UTCVendor advisory
  18. 2026-07-03 09:25 UTCGHSA enrichment
  19. 2026-07-02 08:06 UTCEG score recompute
  20. 2026-07-02 08:06 UTCVendor advisory
  21. 2026-07-02 08:06 UTCGHSA enrichment
  22. 2026-07-01 15:07 UTCEPSS rescore
  23. 2026-07-01 06:47 UTCEG score recompute
  24. 2026-07-01 06:47 UTCVendor advisory
  25. 2026-07-01 06:46 UTCGHSA enrichment
Show 27 more
  1. 2026-06-30 23:22 UTCEPSS rescore
  2. 2026-06-30 05:27 UTCEG score recompute
  3. 2026-06-30 05:26 UTCGHSA enrichment
  4. 2026-06-29 04:07 UTCEG score recompute
  5. 2026-06-29 04:06 UTCGHSA enrichment
  6. 2026-06-28 14:07 UTCEPSS rescore
  7. 2026-06-28 04:56 UTCEPSS rescore
  8. 2026-06-28 04:56 UTCEPSS rescore
  9. 2026-06-28 02:47 UTCEG score recompute
  10. 2026-06-28 02:47 UTCGHSA enrichment
  11. 2026-06-27 03:08 UTCEPSS rescore
  12. 2026-06-27 01:28 UTCEG score recompute
  13. 2026-06-27 01:27 UTCGHSA enrichment
  14. 2026-06-26 00:08 UTCEG score recompute
  15. 2026-06-26 00:08 UTCGHSA enrichment
  16. 2026-06-25 13:49 UTCEPSS rescore
  17. 2026-06-24 22:48 UTCEG score recompute
  18. 2026-06-24 22:48 UTCGHSA enrichment
  19. 2026-06-24 14:05 UTCEPSS rescore
  20. 2026-06-23 21:33 UTCEPSS rescore
  21. 2026-06-23 21:33 UTCEPSS rescore
  22. 2026-06-23 21:28 UTCEG score recompute
  23. 2026-06-23 21:27 UTCGHSA enrichment
  24. 2026-06-22 20:06 UTCEG score recompute
  25. 2026-06-22 20:06 UTCGHSA enrichment
  26. 2026-06-21 18:45 UTCEG score recompute
  27. 2026-06-21 18:45 UTCGHSA enrichment

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-56411?
CVE-2026-56411 is a medium vulnerability published on June 21, 2026. xmlwf in libexpat before 2.8.2 has an integer overflow in endDoctypeDecl via NOTATION declarations.
When was CVE-2026-56411 disclosed?
CVE-2026-56411 was first published in the National Vulnerability Database on June 21, 2026, with the most recent update on June 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56411 actively exploited?
CVE-2026-56411 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-56411?
CVE-2026-56411 has a CVSS v3 base score of 6.9 (NVD).
How do I remediate CVE-2026-56411?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56411, 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

Explore the affected products and dependency analysis for CVE-2026-56411

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