CVE-2026-50260

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-06-05. a secondary CVSS source baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 5 sources updated this week
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 use-after-free flaw was found in the X.Org X server and Xwayland in FreeCounter(). A client that sets up multiple SyncCounters and awaits on those triggers can trigger a use-after-free when destroying those counters via a second client connection. This may be used to crash the server, or for privilege escalation if the X server runs as root.

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
5%
KEV
Not listed

Published

June 5, 2026

Last Modified

August 5, 2026

Advisory Details (5)

Auto-updated Jun 5, 2026
Patch available. Sources: redhat.
generic

Jira

https://redhat.atlassian.net/browse/PSIRTSUPT-16950
generic

X.Org Security Advisory: multiple security issues X.Org X server and Xwayland

https://lists.x.org/archives/xorg-announce/2026-June/003702.html
generic

sync: fix deletion of counters and fences (f5abfb61) · Commits · xorg / xserver · GitLab

https://gitlab.freedesktop.org/xorg/xserver/-/commit/f5abfb61994471023d8c6470428c8e30c411cc0b
redhat

2485385 – (CVE-2026-50260) CVE-2026-50260 xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in FreeCounter()

https://bugzilla.redhat.com/show_bug.cgi?id=2485385
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-50260

Vendor Advisories for CVE-2026-50260(20)

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

Patch Availability(28)

Vendor / EcosystemFixed in / PatchReleasedSource
redhattigervnc-0:1.1.0-25.el6_10.182026-08-03redhat
redhattigervnc-0:1.11.0-8.el8_4.162026-07-27redhat
redhattigervnc-0:1.12.0-15.el8_8.182026-07-27redhat
redhattigervnc-0:1.8.0-36.el7_9.52026-07-27redhat
redhattigervnc-0:1.13.1-8.el9_4.102026-07-27redhat
redhattigervnc-0:1.12.0-6.el8_6.182026-07-27redhat
redhattigervnc-0:1.14.1-11.el9_62026-07-27redhat
redhattigervnc-0:1.12.0-14.el9_2.152026-07-27redhat
redhatxorg-x11-server-Xwayland-0:21.1.3-2.el8_6.72026-07-13redhat
redhatxorg-x11-server-Xwayland-0:21.1.3-13.el8_8.12026-07-13redhat
redhatxorg-x11-server-Xwayland-0:21.1.3-10.el9_2.12026-07-08redhat
redhatxorg-x11-server-Xwayland-0:24.1.5-6.el10_0.12026-07-08redhat
redhatxorg-x11-server-0:1.20.11-19.el8_82026-07-08redhat
redhatxorg-x11-server-0:1.20.10-5.el8_42026-07-08redhat
redhatxorg-x11-server-0:1.20.11-8.el8_62026-07-08redhat
redhatxorg-x11-server-Xwayland-0:23.2.7-6.el9_6.12026-07-08redhat
redhatxorg-x11-server-Xwayland-0:22.1.9-8.el9_4.12026-07-08redhat
redhatxorg-x11-server-0:1.20.11-34.el9_62026-07-07redhat
redhatxorg-x11-server-0:1.20.11-21.el9_22026-07-07redhat
redhatxorg-x11-server-0:1.20.11-29.el9_42026-07-07redhat
redhatxorg-x11-server-0:1.20.4-35.el7_92026-07-07redhat
redhattigervnc-0:1.15.0-7.el9_8.22026-06-25redhat
redhattigervnc-0:1.15.0-10.el8_102026-06-24redhat
redhatxorg-x11-server-Xwayland-0:24.1.9-4.el10_2.22026-06-22redhat
redhatxorg-x11-server-Xwayland-0:24.1.9-4.el9_8.22026-06-17redhat
redhatxorg-x11-server-0:1.20.11-34.el9_8.22026-06-17redhat
redhatxorg-x11-server-Xwayland-0:21.1.3-20.el8_10.22026-06-17redhat
redhatxorg-x11-server-0:1.20.11-28.el8_10.22026-06-17redhat

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.

Affected Packages

(7 across 4 ecosystems)
Debian:12(2)
PackageVulnerable rangeFixed inDependents
xorg-server2:21.1.7-3 ... 2:21.1.7-3+deb12u9 (13 versions)2:21.1.7-3+deb12u13—
xwayland2:22.1.9-1 ... 2:24.1.9-1 (24 versions)——
Debian:13(2)
PackageVulnerable rangeFixed inDependents
xorg-server2:21.1.16-1.3, 2:21.1.16-1.3+deb13u1, 2:21.1.16-1.3+deb13u22:21.1.16-1.3+deb13u3—
xwayland2:24.1.10-1 ... 2:24.1.9-1 (7 versions)——
Debian:14(2)
PackageVulnerable rangeFixed inDependents
xorg-server2:21.1.16-1.3 ... 2:21.1.22-1 (6 versions)2:21.1.23-1—
xwayland2:24.1.10-1, 2:24.1.11-1, 2:24.1.6-1, 2:24.1.8-1, 2:24.1.9-12:24.1.12-1—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
xorg-server2:1.20.11-1 ... 2:21.1.9-1+hurd.1 (62 versions)——

Weakness Classification(1)

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

Additional Vendor Advisories

(7)

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 6× in last 7d / 43× 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 357 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-50260?
CVE-2026-50260 is a high vulnerability published on June 5, 2026. A use-after-free flaw was found in the X.Org X server and Xwayland in FreeCounter(). A client that sets up multiple SyncCounters and awaits on those triggers can trigger a use-after-free when destroying those counters via a second client connection. This may be used to crash the server, or for…
When was CVE-2026-50260 disclosed?
CVE-2026-50260 was first published in the National Vulnerability Database on June 5, 2026, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-50260 actively exploited?
CVE-2026-50260 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 95.1% of all scored CVEs.
What is the CVSS score of CVE-2026-50260?
CVE-2026-50260 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-50260?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-50260, 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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