CVE-2026-34001

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-04-23. a secondary CVSS source baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: None knownExposed: 0

A fix is available — apply it.

A flaw was found in the X.Org X server. This use-after-free vulnerability occurs in the XSYNC fence triggering logic, specifically within the miSyncTriggerFence() function. An attacker with access to the X11 server can exploit this without user interaction, leading to a server crash and potentially enabling memory corruption. This could result in a denial of service or further compromise of the system.

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
35(Track)
EG Risk 35/100SSVC: Track

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
Severity78% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
18%
KEV
Not listed

Published

April 23, 2026

Last Modified

July 15, 2026

Advisory Details (7)

Auto-updated Apr 29, 2026
Patch available. Sources: redhat.
redhat Patch Available

2451109 – (CVE-2026-34001) CVE-2026-34001 xorg: xwayland: X.Org X server: Use-after-free vulnerability leads to server crash and potential memory corruption

Affected: Red Hat Enterprise Linux 9

https://bugzilla.redhat.com/show_bug.cgi?id=2451109
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-34001
redhat Patch Available

Affected: Red Hat Enterprise Linux 8.

https://access.redhat.com/errata/RHSA-2026:11692
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.

https://access.redhat.com/errata/RHSA-2026:11388
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.

https://access.redhat.com/errata/RHSA-2026:11369
redhat Patch Available

Affected: Red Hat Enterprise Linux 10.

https://access.redhat.com/errata/RHSA-2026:11352
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.

https://access.redhat.com/errata/RHSA-2026:10739

Vendor Advisories for CVE-2026-34001(20)

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

Patch Availability(30)

Vendor / EcosystemFixed in / PatchReleasedSource
redhattigervnc-0:1.12.0-6.el8_6.172026-06-08redhat
redhattigervnc-0:1.1.0-25.el6_10.162026-06-04redhat
redhattigervnc-0:1.11.0-8.el8_4.152026-06-04redhat
redhattigervnc-0:1.12.0-15.el8_8.172026-06-04redhat
redhattigervnc-0:1.8.0-36.el7_9.42026-06-02redhat
redhattigervnc-0:1.14.1-10.el9_62026-06-02redhat
redhattigervnc-0:1.11.0-22.el9_0.172026-05-28redhat
redhatxorg-x11-server-Xwayland-0:21.1.3-2.el8_6.62026-05-28redhat
redhatxorg-x11-server-0:1.20.11-7.el8_62026-05-28redhat
redhatxorg-x11-server-0:1.20.10-4.el8_42026-05-28redhat
redhatxorg-x11-server-0:1.20.11-13.el9_02026-05-28redhat
redhatxorg-x11-server-Xwayland-0:21.1.3-13.el8_82026-05-28redhat
redhatxorg-x11-server-0:1.20.11-18.el8_82026-05-28redhat
redhatxorg-x11-server-0:1.20.11-33.el9_62026-05-26redhat
redhatxorg-x11-server-Xwayland-0:24.1.5-6.el10_02026-05-26redhat
redhatxorg-x11-server-0:1.20.11-28.el9_42026-05-26redhat
redhatxorg-x11-server-Xwayland-0:22.1.9-8.el9_42026-05-26redhat
redhattigervnc-0:1.12.0-14.el9_2.142026-05-26redhat
redhatxorg-x11-server-Xwayland-0:21.1.3-5.el9_02026-05-26redhat
redhatxorg-x11-server-0:1.20.11-20.el9_22026-05-26redhat
redhatxorg-x11-server-Xwayland-0:23.2.7-6.el9_62026-05-26redhat
redhatxorg-x11-server-0:1.20.4-34.el7_92026-05-26redhat
redhatxorg-x11-server-Xwayland-0:21.1.3-10.el9_22026-05-26redhat
redhattigervnc-0:1.13.1-8.el9_4.92026-05-26redhat
redhatxorg-x11-server-Xwayland-0:24.1.9-4.el10_22026-05-19redhat
redhattigervnc-0:1.15.0-7.el9_8.12026-05-19redhat
redhatxorg-x11-server-Xwayland-0:24.1.9-4.el9_82026-05-19redhat
redhatxorg-x11-server-0:1.20.11-34.el9_82026-05-19redhat
redhattigervnc-0:1.15.0-9.el8_102026-05-04redhat
redhatxorg-x11-server-0:1.20.11-28.el8_102026-04-29redhat

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.

Additional Vendor Advisories

(16)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 12× in last 7d / 41× 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.

Showing the most recent 100 of 137 total refreshes for this CVE.

  1. 2026-07-26 14:54 UTCEPSS rescore
  2. 2026-07-26 14:54 UTCEPSS rescore
  3. 2026-07-25 14:18 UTCEPSS rescore
  4. 2026-07-25 14:18 UTCEPSS rescore
  5. 2026-07-24 14:17 UTCEPSS rescore
  6. 2026-07-24 14:17 UTCEPSS rescore
  7. 2026-07-23 14:18 UTCEPSS rescore
  8. 2026-07-23 14:18 UTCEPSS rescore
  9. 2026-07-23 03:09 UTCEG score recompute
  10. 2026-07-22 14:08 UTCEPSS rescore
  11. 2026-07-21 15:24 UTCEPSS rescore
  12. 2026-07-20 17:08 UTCEPSS rescore
  13. 2026-07-19 14:31 UTCEPSS rescore
  14. 2026-07-19 02:29 UTCEPSS rescore
  15. 2026-07-18 10:04 UTCEPSS rescore
  16. 2026-07-16 17:03 UTCEPSS rescore
  17. 2026-07-15 16:57 UTCEPSS rescore
  18. 2026-07-15 16:57 UTCEPSS rescore
  19. 2026-07-15 02:00 UTCEPSS rescore
  20. 2026-07-13 22:30 UTCEPSS rescore
  21. 2026-07-13 06:13 UTCEPSS rescore
  22. 2026-07-13 06:13 UTCEPSS rescore
  23. 2026-07-12 05:46 UTCEPSS rescore
  24. 2026-07-11 08:27 UTCEPSS rescore
  25. 2026-07-09 19:10 UTCEPSS rescore
Show 75 more
  1. 2026-07-08 15:15 UTCEPSS rescore
  2. 2026-07-07 13:46 UTCEPSS rescore
  3. 2026-07-06 16:27 UTCEPSS rescore
  4. 2026-07-06 16:27 UTCEPSS rescore
  5. 2026-07-06 02:23 UTCEPSS rescore
  6. 2026-07-06 02:23 UTCEPSS rescore
  7. 2026-07-05 02:30 UTCEPSS rescore
  8. 2026-07-04 06:31 UTCEPSS rescore
  9. 2026-07-01 15:06 UTCEPSS rescore
  10. 2026-06-30 23:22 UTCEPSS rescore
  11. 2026-06-29 14:06 UTCEPSS rescore
  12. 2026-06-29 14:06 UTCEPSS rescore
  13. 2026-06-28 14:07 UTCEPSS rescore
  14. 2026-06-28 14:07 UTCEPSS rescore
  15. 2026-06-28 04:56 UTCEPSS rescore
  16. 2026-06-28 04:56 UTCEPSS rescore
  17. 2026-06-27 03:08 UTCEPSS rescore
  18. 2026-06-25 13:49 UTCEPSS rescore
  19. 2026-06-25 13:49 UTCEPSS rescore
  20. 2026-06-24 14:05 UTCEPSS rescore
  21. 2026-06-23 21:33 UTCEPSS rescore
  22. 2026-06-23 21:33 UTCEPSS rescore
  23. 2026-06-22 14:25 UTCEPSS rescore
  24. 2026-06-22 14:25 UTCEPSS rescore
  25. 2026-06-21 14:56 UTCEPSS rescore
  26. 2026-06-21 14:56 UTCEPSS rescore
  27. 2026-06-21 01:59 UTCEPSS rescore
  28. 2026-06-19 19:25 UTCEPSS rescore
  29. 2026-06-19 19:25 UTCEPSS rescore
  30. 2026-06-18 17:52 UTCEPSS rescore
  31. 2026-06-18 17:52 UTCEPSS rescore
  32. 2026-06-17 17:53 UTCEPSS rescore
  33. 2026-06-16 17:52 UTCEPSS rescore
  34. 2026-06-15 17:49 UTCEPSS rescore
  35. 2026-06-15 02:27 UTCVendor advisory
  36. 2026-06-15 02:27 UTCGHSA enrichment
  37. 2026-06-14 23:18 UTCEPSS rescore
  38. 2026-06-14 12:20 UTCVendor advisory
  39. 2026-06-14 12:20 UTCGHSA enrichment
  40. 2026-06-12 02:18 UTCVendor advisory
  41. 2026-06-12 02:18 UTCGHSA enrichment
  42. 2026-06-11 14:27 UTCVendor advisory
  43. 2026-06-11 14:26 UTCGHSA enrichment
  44. 2026-06-11 14:00 UTCEPSS rescore
  45. 2026-06-10 22:18 UTCEPSS rescore
  46. 2026-06-10 15:02 UTCVendor advisory
  47. 2026-06-10 15:02 UTCGHSA enrichment
  48. 2026-06-10 03:11 UTCVendor advisory
  49. 2026-06-10 03:11 UTCGHSA enrichment
  50. 2026-06-09 15:19 UTCVendor advisory
  51. 2026-06-09 15:19 UTCGHSA enrichment
  52. 2026-06-09 03:28 UTCVendor advisory
  53. 2026-06-09 03:28 UTCGHSA enrichment
  54. 2026-06-08 14:17 UTCEPSS rescore
  55. 2026-06-08 14:17 UTCEPSS rescore
  56. 2026-06-08 05:55 UTCVendor advisory
  57. 2026-06-08 05:55 UTCGHSA enrichment
  58. 2026-06-07 18:04 UTCVendor advisory
  59. 2026-06-07 18:04 UTCGHSA enrichment
  60. 2026-06-07 15:25 UTCEPSS rescore
  61. 2026-06-07 15:25 UTCEPSS rescore
  62. 2026-06-07 15:25 UTCEPSS rescore
  63. 2026-06-07 06:12 UTCVendor advisory
  64. 2026-06-07 06:12 UTCGHSA enrichment
  65. 2026-06-06 18:20 UTCVendor advisory
  66. 2026-06-06 18:20 UTCGHSA enrichment
  67. 2026-06-06 13:47 UTCEPSS rescore
  68. 2026-06-06 13:47 UTCEPSS rescore
  69. 2026-06-06 04:43 UTCVendor advisory
  70. 2026-06-06 04:43 UTCGHSA enrichment
  71. 2026-06-05 16:01 UTCVendor advisory
  72. 2026-06-05 16:01 UTCGHSA enrichment
  73. 2026-06-05 06:10 UTCEPSS rescore
  74. 2026-06-05 06:10 UTCEPSS rescore
  75. 2026-06-05 03:05 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-34001?
CVE-2026-34001 is a high vulnerability published on April 23, 2026. A flaw was found in the X.Org X server. This use-after-free vulnerability occurs in the XSYNC fence triggering logic, specifically within the miSyncTriggerFence() function. An attacker with access to the X11 server can exploit this without user interaction, leading to a server crash and potentially…
When was CVE-2026-34001 disclosed?
CVE-2026-34001 was first published in the National Vulnerability Database on April 23, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-34001 actively exploited?
CVE-2026-34001 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 81.9% of all scored CVEs.
What is the CVSS score of CVE-2026-34001?
CVE-2026-34001 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-34001?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-34001, 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-2026-34001

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