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.
CVE-2026-50260
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.
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- 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 computedSeverity78% × 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
July 27, 2026
Advisory Details (5)
Auto-updated Jun 5, 2026X.Org Security Advisory: multiple security issues X.Org X server and Xwayland
https://lists.x.org/archives/xorg-announce/2026-June/003702.htmlsync: fix deletion of counters and fences (f5abfb61) · Commits · xorg / xserver · GitLab
https://gitlab.freedesktop.org/xorg/xserver/-/commit/f5abfb61994471023d8c6470428c8e30c411cc0b2485385 – (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=2485385Vendor 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.
- RHSA-2026:46460Red Hat Product SecurityHigh
Red Hat Security Advisory: tigervnc security update
- RHSA-2026:46456Red Hat Product SecurityHigh
Red Hat Security Advisory: tigervnc security update
- RHSA-2026:46382Red Hat Product SecurityHigh
Red Hat Security Advisory: tigervnc security update
- RHSA-2026:46377Red Hat Product SecurityHigh
Red Hat Security Advisory: tigervnc security update
- RHSA-2026:38810Red Hat Product SecurityHigh
Red Hat Security Advisory: xorg-x11-server-Xwayland security update
- RHSA-2026:38502Red Hat Product SecurityHigh
Red Hat Security Advisory: xorg-x11-server-Xwayland security update
- RHSA-2026:36798Red Hat Product SecurityHigh
Red Hat Security Advisory: xorg-x11-server-Xwayland security update
- RHSA-2026:36792Red Hat Product SecurityHigh
Red Hat Security Advisory: xorg-x11-server security update
- +12 more
Patch Availability(27)
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
(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.
- Microsoft MSRCCVE-2026-502602026-06-09
Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: use-after-free in freecounter()
- Red HatRHSA-2026:26562IMPORTANT2026-06-02
RHSA-2026:26562 — Important
- Red HatRHSA-2026:26590IMPORTANT2026-06-02
RHSA-2026:26590 — Important
- Red HatRHSA-2026:26610IMPORTANT2026-06-02
RHSA-2026:26610 — Important
- Red HatRHSA-2026:26709IMPORTANT2026-06-02
RHSA-2026:26709 — Important
- Red HatRHSA-2026:46385IMPORTANT2026-06-02
RHSA-2026:46385 — Important
- Red HatRHSA-2026:46392IMPORTANT2026-06-02
RHSA-2026:46392 — Important
Data Freshness Timeline
(refreshed 39× in last 7d / 112× 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 207 total refreshes for this CVE.
- 2026-07-28 03:04 UTCEG score recompute
- 2026-07-28 03:04 UTCVendor advisory
- 2026-07-28 03:04 UTCGHSA enrichment
- 2026-07-27 13:25 UTCEG score recompute
- 2026-07-27 13:25 UTCVendor advisory
- 2026-07-27 13:25 UTCGHSA enrichment
- 2026-07-27 12:40 UTCEG score recompute
- 2026-07-27 12:40 UTCVendor advisory
- 2026-07-27 12:39 UTCGHSA enrichment
- 2026-07-27 10:23 UTCEG score recompute
- 2026-07-27 10:23 UTCVendor advisory
- 2026-07-27 10:23 UTCGHSA enrichment
- 2026-07-27 10:12 UTCEG score recompute
- 2026-07-27 10:12 UTCVendor advisory
- 2026-07-27 10:12 UTCGHSA enrichment
- 2026-07-27 08:21 UTCVendor advisory
- 2026-07-27 08:21 UTCGHSA enrichment
- 2026-07-27 07:22 UTCEG score recompute
- 2026-07-27 07:22 UTCVendor advisory
- 2026-07-27 07:22 UTCGHSA enrichment
- 2026-07-27 06:24 UTCEG score recompute
- 2026-07-27 06:24 UTCVendor advisory
- 2026-07-27 06:24 UTCGHSA enrichment
- 2026-07-27 04:24 UTCEG score recompute
- 2026-07-27 04:24 UTCVendor advisory
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- 2026-07-27 04:23 UTCGHSA enrichment
- 2026-07-27 03:52 UTCEG score recompute
- 2026-07-27 03:52 UTCVendor advisory
- 2026-07-27 03:52 UTCGHSA enrichment
- 2026-07-26 21:56 UTCEG score recompute
- 2026-07-26 21:56 UTCVendor advisory
- 2026-07-26 21:56 UTCGHSA enrichment
- 2026-07-26 14:54 UTCEPSS rescore
- 2026-07-25 14:18 UTCEPSS rescore
- 2026-07-24 14:18 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 03:18 UTCEG score recompute
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:25 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 02:29 UTCEPSS rescore
- 2026-07-16 17:03 UTCEPSS rescore
- 2026-07-16 11:57 UTCVendor advisory
- 2026-07-16 11:57 UTCGHSA enrichment
- 2026-07-15 22:46 UTCVendor advisory
- 2026-07-15 22:46 UTCGHSA enrichment
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 02:00 UTCEPSS rescore
- 2026-07-15 02:00 UTCEPSS rescore
- 2026-07-14 16:08 UTCVendor advisory
- 2026-07-14 16:08 UTCGHSA enrichment
- 2026-07-14 03:04 UTCVendor advisory
- 2026-07-14 03:04 UTCGHSA enrichment
- 2026-07-13 22:31 UTCEPSS rescore
- 2026-07-13 06:13 UTCEPSS rescore
- 2026-07-13 06:13 UTCEPSS rescore
- 2026-07-12 12:31 UTCVendor advisory
- 2026-07-12 12:31 UTCGHSA enrichment
- 2026-07-12 05:46 UTCEPSS rescore
- 2026-07-11 18:19 UTCVendor advisory
- 2026-07-11 18:19 UTCGHSA enrichment
- 2026-07-11 08:27 UTCEPSS rescore
- 2026-07-11 08:27 UTCEPSS rescore
- 2026-07-11 05:15 UTCVendor advisory
- 2026-07-11 05:15 UTCGHSA enrichment
- 2026-07-09 19:10 UTCEPSS rescore
- 2026-07-09 19:10 UTCEPSS rescore
- 2026-07-09 10:27 UTCVendor advisory
- 2026-07-09 10:27 UTCGHSA enrichment
- 2026-07-08 21:32 UTCVendor advisory
- 2026-07-08 21:32 UTCGHSA enrichment
- 2026-07-08 15:16 UTCEPSS rescore
- 2026-07-08 15:16 UTCEPSS rescore
- 2026-07-08 07:51 UTCVendor advisory
- 2026-07-08 07:51 UTCGHSA enrichment
- 2026-07-07 13:46 UTCEPSS rescore
- 2026-07-07 13:46 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-05 18:38 UTCVendor advisory
- 2026-07-05 18:38 UTCGHSA enrichment
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-04 20:49 UTCVendor advisory
- 2026-07-04 20:48 UTCGHSA enrichment
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-03 16:52 UTCVendor advisory
- 2026-07-03 16:52 UTCGHSA enrichment
- 2026-07-02 22:15 UTCVendor advisory
- 2026-07-02 22:14 UTCGHSA enrichment
- 2026-07-02 09:13 UTCVendor advisory
- 2026-07-02 09:13 UTCGHSA enrichment
- 2026-07-01 20:16 UTCVendor advisory
- 2026-07-01 20:16 UTCGHSA enrichment
- 2026-07-01 15:07 UTCEPSS rescore
- 2026-07-01 07:19 UTCVendor advisory
- 2026-07-01 07:19 UTCGHSA enrichment
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-30 18:14 UTCVendor advisory
Related CVEs(same vendor + same CWE)
Same vendor
10 shownredhat
- CVE-2001-0825EG 10.0HIGH
- CVE-2001-0554EG 10.0EPSS p98HIGH
- CVE-2001-0414EG 10.0EPSS p100HIGH
- CVE-2001-0191EG 10.0EPSS p92HIGH
- CVE-2001-0301EG 10.0EPSS p90HIGH
- CVE-2001-0197EG 10.0EPSS p96HIGH
- CVE-2001-0233EG 10.0EPSS p96HIGH
- CVE-2001-0010EG 10.0EPSS p98HIGH
- CVE-2001-0011EG 10.0EPSS p94HIGH
- CVE-2001-0013EG 10.0EPSS p95HIGH
Frequently asked(5)
What is CVE-2026-50260?
When was CVE-2026-50260 disclosed?
Is CVE-2026-50260 actively exploited?
What is the CVSS score of CVE-2026-50260?
How do I remediate CVE-2026-50260?
Dependency Blast Radius
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