CVE-2026-33999: xorg-x11-server-Xwayland security update
Affects xorg-x11-server-XwaylandSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 7.8 High : upgrade to 21.1.3-20.el8_10 soon.
Data as of 27 Oct 2026, 00:15 UTC
- Patch
- Available – fixed in 21.1.3-20.el8_10
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 23 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade the AlmaLinux xorg-x11-server-Xwayland package to 21.1.3-20.el8_10.
Patches and advisories
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| AlmaLinux 8xorg-x11-server-Xwayland | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A security update is available and should be applied promptly. The fixed version is 21.1.3-20.el8_10. Users should update their xorg-x11-server-Xwayland package to this version or later to remediate these vulnerabilities. No additional mitigation steps are indicated by the vendor advisory.
Description
Multiple security vulnerabilities have been identified in xorg-x11-server-Xwayland, an X server for running X clients under Wayland. These include a denial of service via integer underflow in XKB compatibility map handling (CVE-2026-33999), a use-after-free vulnerability that can cause server crashes and potential memory corruption (CVE-2026-34001), and information exposure plus denial of service via out-of-bounds memory access (CVE-2026-34003). A security update fixing these issues is available in version 21.1.3-20.el8_10.
References
- access.redhat.com/errata/RHSA-2026:11656 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-33999 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-34001 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-34003 (opens in a new tab)
- bugzilla.redhat.com/2451106 (opens in a new tab)
- bugzilla.redhat.com/2451109 (opens in a new tab)
- bugzilla.redhat.com/2451113 (opens in a new tab)
- errata.almalinux.org/8/ALSA-2026-11656.html (opens in a new tab)