CVE-2026-88806

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-21. A secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
7.5EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 7.5Exploit: None knownExposed services: Not assessed

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

A malicious X server could exploit a buffer overflow in libX11 before 1.8.14 during handling of XkbGetMap overflowing the key_sym_map.

CVSS v3
7.5
EG Score
7.5HIGHhigh confidence
EG Risk
34
EG Risk 34/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
EPSS PROB
0.2%
EPSS %ILE
8th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 21, 2026

Last Modified

September 22, 2026

Advisory Details (1)

Auto-updated Sep 21, 2026
No patch confirmed yet.
generic

xkb: Check the keysym range in _XkbReadKeyActions (CVE-2026-88806) (!309) · Merge requests · xorg / lib / libX11 · GitLab

https://gitlab.freedesktop.org/xorg/lib/libx11/-/merge_requests/309

Vendor Advisories for CVE-2026-88806(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 42× in last 7d / 86× 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. 2026-10-04 03:17 UTCVendor advisory
  2. 2026-10-04 03:17 UTCGHSA enrichment
  3. 2026-10-03 16:27 UTCEG score recompute
  4. 2026-10-03 16:27 UTCVendor advisory
  5. 2026-10-03 16:27 UTCGHSA enrichment
  6. 2026-10-03 05:37 UTCVendor advisory
  7. 2026-10-03 05:37 UTCGHSA enrichment
  8. 2026-10-02 18:47 UTCEG score recompute
  9. 2026-10-02 18:47 UTCVendor advisory
  10. 2026-10-02 18:47 UTCGHSA enrichment
  11. 2026-10-02 07:54 UTCVendor advisory
  12. 2026-10-02 07:54 UTCGHSA enrichment
  13. 2026-10-01 21:04 UTCEG score recompute
  14. 2026-10-01 21:04 UTCVendor advisory
  15. 2026-10-01 21:04 UTCGHSA enrichment
  16. 2026-10-01 19:51 UTCEPSS rescore
  17. 2026-10-01 10:14 UTCVendor advisory
  18. 2026-10-01 10:14 UTCGHSA enrichment
  19. 2026-09-30 23:24 UTCEG score recompute
  20. 2026-09-30 23:24 UTCVendor advisory
  21. 2026-09-30 23:23 UTCGHSA enrichment
  22. 2026-09-30 15:04 UTCEPSS rescore
  23. 2026-09-30 12:31 UTCVendor advisory
  24. 2026-09-30 12:31 UTCGHSA enrichment
  25. 2026-09-30 01:38 UTCEG score recompute
Show 61 more
  1. 2026-09-30 01:38 UTCVendor advisory
  2. 2026-09-30 01:38 UTCGHSA enrichment
  3. 2026-09-29 14:48 UTCVendor advisory
  4. 2026-09-29 14:48 UTCGHSA enrichment
  5. 2026-09-29 03:56 UTCEG score recompute
  6. 2026-09-29 03:56 UTCVendor advisory
  7. 2026-09-29 03:55 UTCGHSA enrichment
  8. 2026-09-28 17:04 UTCEG score recompute
  9. 2026-09-28 17:04 UTCVendor advisory
  10. 2026-09-28 17:04 UTCGHSA enrichment
  11. 2026-09-28 13:52 UTCEPSS rescore
  12. 2026-09-28 06:04 UTCVendor advisory
  13. 2026-09-28 06:04 UTCGHSA enrichment
  14. 2026-09-27 19:14 UTCEG score recompute
  15. 2026-09-27 19:14 UTCVendor advisory
  16. 2026-09-27 19:14 UTCGHSA enrichment
  17. 2026-09-27 13:48 UTCEPSS rescore
  18. 2026-09-27 08:23 UTCVendor advisory
  19. 2026-09-27 08:23 UTCGHSA enrichment
  20. 2026-09-26 21:33 UTCEG score recompute
  21. 2026-09-26 21:33 UTCVendor advisory
  22. 2026-09-26 21:33 UTCGHSA enrichment
  23. 2026-09-26 15:59 UTCEPSS rescore
  24. 2026-09-26 10:42 UTCEG score recompute
  25. 2026-09-26 10:42 UTCVendor advisory
  26. 2026-09-26 10:41 UTCGHSA enrichment
  27. 2026-09-25 23:49 UTCVendor advisory
  28. 2026-09-25 23:49 UTCGHSA enrichment
  29. 2026-09-25 12:57 UTCVendor advisory
  30. 2026-09-25 12:57 UTCGHSA enrichment
  31. 2026-09-25 02:05 UTCVendor advisory
  32. 2026-09-25 02:05 UTCGHSA enrichment
  33. 2026-09-24 15:14 UTCEG score recompute
  34. 2026-09-24 15:14 UTCVendor advisory
  35. 2026-09-24 15:14 UTCGHSA enrichment
  36. 2026-09-24 14:04 UTCEPSS rescore
  37. 2026-09-24 04:24 UTCEG score recompute
  38. 2026-09-24 04:24 UTCVendor advisory
  39. 2026-09-24 04:24 UTCGHSA enrichment
  40. 2026-09-23 17:54 UTCEPSS rescore
  41. 2026-09-23 17:33 UTCVendor advisory
  42. 2026-09-23 17:33 UTCGHSA enrichment
  43. 2026-09-23 06:43 UTCVendor advisory
  44. 2026-09-23 06:43 UTCGHSA enrichment
  45. 2026-09-22 19:52 UTCEG score recompute
  46. 2026-09-22 19:52 UTCVendor advisory
  47. 2026-09-22 19:52 UTCGHSA enrichment
  48. 2026-09-22 16:01 UTCEPSS rescore
  49. 2026-09-22 15:22 UTCVendor advisory
  50. 2026-09-22 15:22 UTCGHSA enrichment
  51. 2026-09-22 04:32 UTCEG score recompute
  52. 2026-09-22 04:31 UTCGHSA enrichment
  53. 2026-09-22 04:01 UTCEG score recompute
  54. 2026-09-22 04:01 UTCGHSA enrichment
  55. 2026-09-22 02:13 UTCEG score recompute
  56. 2026-09-22 02:13 UTCGHSA enrichment
  57. 2026-09-21 15:22 UTCEG score recompute
  58. 2026-09-21 14:56 UTCEG score recompute
  59. 2026-09-21 14:21 UTCEG score recompute
  60. 2026-09-21 13:45 UTCEG score recompute
  61. 2026-09-21 13:45 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-88806?
CVE-2026-88806 is a high vulnerability published on September 21, 2026. A malicious X server could exploit a buffer overflow in libX11 before 1.8.14 during handling of XkbGetMap overflowing the keysymmap.
When was CVE-2026-88806 disclosed?
CVE-2026-88806 was first published on September 21, 2026, with the most recent update on September 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-88806 actively exploited?
CVE-2026-88806 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (8th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-88806?
CVE-2026-88806 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-88806?
No fix for CVE-2026-88806 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-88806 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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