How to Fix CVE-2026-34001: Red Hat Enterprise Linux 10 (Bundle Sibling)
By Sai Kiran Pandrala
Last verified: 2026-05-25
CVE-2026-34001 is a sibling vulnerability in the same vendor advisory as CVE-2026-33999. Applying the patched build named in the primary write-up closes this CVE as well.
| Severity | CVSS 7.8 - High |
|---|---|
| Actively exploited? | Not currently in CISA KEV |
| Affected | Same as the bundle - see CVE-2026-33999 |
| Fixed in | Same patched build as CVE-2026-33999 (0:24.1.5-6.el10_1, 0:24.1.9-4.el10_2, 0:21.1.3-20.el8_10, 0:1.20.11-28.el8_10, 0:1.15.0-9.el8_10, 0:1.15.0-6.el9_7.1) |
| Type (CWE) | CWE-825: Expired Pointer Dereference |
What's different about CVE-2026-34001?
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.
The technical impact and remediation are identical to the primary CVE in the bundle. The same vendor patch closes both.
How to fix CVE-2026-34001
Apply the patched build per the primary write-up: How to Fix CVE-2026-33999.
The patch installation procedure, verification commands, and interim mitigations are documented there. Reusing one runbook keeps the rollout consistent across the bundle.
Frequently asked questions
Is CVE-2026-34001 fixed by the same patch as CVE-2026-33999?
Yes. CVE-2026-34001 ships in the same vendor advisory as CVE-2026-33999. Applying the patched build named in the primary write-up closes both.
What is the CVSS score for CVE-2026-34001?
The CVSS base score is 7.8 (High).
Is it being exploited?
It is not currently listed in CISA KEV.
References
- Official vendor advisory: https://access.redhat.com/errata/RHSA-2026:10739
- NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2026-34001
- CISA KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog
- Primary write-up: How to Fix CVE-2026-33999
*Part of the Red Hat Enterprise Linux 10 bundle. Full procedure at CVE-2026-33999.*