CVE-2026-56003

HIGHNVD 8.88.5▼
EchelonGraph scoreHIGH confidence

Score 8.5 from GitHub Security Advisory (severity: HIGH) published 2026-07-08. NVD baseline CVSS 8.8; sources differ by 0.3.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 5 sources updated this week
8.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 8.8Exploit: NoneExposed: 0

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

A heap buffer overflow due to missing size checking in the property buffer when parsing PCF files in libXfont2 ComputeScaledProperties() before libXfont2 before 2.0.8 could be used by attackers using authenticated X clients to execute code within the X server.

CVSS v3
8.8
EG Score
8.5(high)
EPSS
46.6%
KEV
Not listed

Published

July 8, 2026

Last Modified

July 9, 2026

Advisory Details (2)

Auto-updated Jul 8, 2026
No patch confirmed yet.
generic

oss-security - FW: X.Org Security Advisory: multiple security issues in libXfont2

https://www.openwall.com/lists/oss-security/2026/07/08/1
generic

bitscale: add bounds check to computeProps for property buffer (dff957a5) · Commits · xorg / lib / libXfont · GitLab

https://gitlab.freedesktop.org/xorg/lib/libxfont/-/commit/dff957a5158da038a282a59a31fe736702732939

Vendor Advisories for CVE-2026-56003(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 33× in last 7d / 33× 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. 2026-07-13 22:31 UTCEPSS rescore
  2. 2026-07-13 19:37 UTCEG score recompute
  3. 2026-07-13 19:36 UTCGHSA enrichment
  4. 2026-07-13 06:39 UTCEG score recompute
  5. 2026-07-13 06:38 UTCGHSA enrichment
  6. 2026-07-13 06:13 UTCEPSS rescore
  7. 2026-07-13 06:13 UTCEPSS rescore
  8. 2026-07-12 17:39 UTCEG score recompute
  9. 2026-07-12 17:39 UTCGHSA enrichment
  10. 2026-07-12 05:46 UTCEPSS rescore
  11. 2026-07-12 04:42 UTCEG score recompute
  12. 2026-07-12 04:42 UTCGHSA enrichment
  13. 2026-07-11 15:45 UTCEG score recompute
  14. 2026-07-11 15:45 UTCGHSA enrichment
  15. 2026-07-11 08:27 UTCEPSS rescore
  16. 2026-07-11 08:27 UTCEPSS rescore
  17. 2026-07-11 02:48 UTCEG score recompute
  18. 2026-07-11 02:48 UTCGHSA enrichment
  19. 2026-07-10 13:51 UTCEG score recompute
  20. 2026-07-10 13:51 UTCGHSA enrichment
  21. 2026-07-10 00:53 UTCEG score recompute
  22. 2026-07-10 00:53 UTCGHSA enrichment
  23. 2026-07-09 19:48 UTCNVD updateCVSS v3 → 8.8
  24. 2026-07-09 19:10 UTCEPSS rescore
  25. 2026-07-09 19:10 UTCEPSS rescore
Show 8 more
  1. 2026-07-09 11:55 UTCEG score recompute
  2. 2026-07-09 11:55 UTCGHSA enrichment
  3. 2026-07-08 22:58 UTCEG score recompute
  4. 2026-07-08 22:58 UTCGHSA enrichment
  5. 2026-07-08 15:16 UTCEPSS rescore
  6. 2026-07-08 15:16 UTCEPSS rescore
  7. 2026-07-08 10:01 UTCEG score recompute
  8. 2026-07-08 10:00 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-56003?
CVE-2026-56003 is a high vulnerability published on July 8, 2026. A heap buffer overflow due to missing size checking in the property buffer when parsing PCF files in libXfont2 ComputeScaledProperties() before libXfont2 before 2.0.8 could be used by attackers using authenticated X clients to execute code within the X server.
When was CVE-2026-56003 disclosed?
CVE-2026-56003 was first published in the National Vulnerability Database on July 8, 2026, with the most recent update on July 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56003 actively exploited?
CVE-2026-56003 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 46.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-56003?
CVE-2026-56003 has a CVSS v3 base score of 8.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 8.5.
How do I remediate CVE-2026-56003?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56003, 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-2026-56003

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