Red Hat Enterprise Linux 10: Use After Free
CVE-2026-50260 is a high-severity use after free vulnerability in Red Hat Enterprise Linux 10 from Red Hat, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.15% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update X Server to 21.1.23 or a later version.
- Update Xwayland to 24.1.12 or a later version.
- Read the advisory on lists.x.org for workarounds and exact fixed builds.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (redhat.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA (redhat.com) |
| CVSS 3.1 | 7.8 | High | CNA |
Official description
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- lists.x.org/archives/xorg-announce/2026-June/003702.htmlMailing List
- redhat.atlassian.net/browse/PSIRTSUPT-16950Permissions Required
Patches and release notes
Third-party and government advisories
- access.redhat.com/security/cve/CVE-2026-50260Third Party Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2485385Issue Tracking, Third Party Advisory
Other references
- access.redhat.com/errata/RHSA-2026:26562
- access.redhat.com/errata/RHSA-2026:26566
- access.redhat.com/errata/RHSA-2026:26590
- access.redhat.com/errata/RHSA-2026:26610
- access.redhat.com/errata/RHSA-2026:26709
- access.redhat.com/errata/RHSA-2026:28923
- access.redhat.com/errata/RHSA-2026:29844
- access.redhat.com/errata/RHSA-2026:36083
- access.redhat.com/errata/RHSA-2026:36085
- access.redhat.com/errata/RHSA-2026:36086
- access.redhat.com/errata/RHSA-2026:36087
- access.redhat.com/errata/RHSA-2026:36632
- access.redhat.com/errata/RHSA-2026:36633
- access.redhat.com/errata/RHSA-2026:36634
- access.redhat.com/errata/RHSA-2026:36768
Other vulnerabilities in Red Hat Enterprise Linux 10
- 8.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.9 High severity
- 7.3 High severity
- 7.5 High severity
Recent Use After Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
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