What is CVE-2026-33999?

CVE-2026-33999 is a security advisory published by Microsoft Security Response Center (MSRC) with Medium severity. Xorg: xwayland: x.org x server: denial of service via integer underflow in xkb compatibility map handling

Which CVE IDs does CVE-2026-33999 cover?

CVE-2026-33999 covers the following CVE IDs: CVE-2026-33999. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-33999?

CVE-2026-33999 has a CVSS v3 base score of 6.6, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2026-33999?

CVE-2026-33999 affects 4 products, including: azl3 xorg-x11-server-Xwayland 24.1.6-3 on Azure Linux 3.0; azl3 xorg-x11-server-Xwayland 24.1.6-4 on Azure Linux 3.0; cbl2 xorg-x11-server 1.20.10-16 on CBL Mariner 2.0; cbl2 xorg-x11-server 1.20.10-16 on CBL-Mariner 2.0.

CVE-2026-33999MediumCVSS 6.6

Xorg: xwayland: x.org x server: denial of service via integer underflow in xkb compatibility map handling

Vendor

Microsoft Security Response Center (MSRC)

Published

June 2, 2026

Last Modified

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🔗 CVE IDs covered (1)

CVE-2026-33999 →

🎯 Affected products4

azl3 xorg-x11-server-Xwayland 24.1.6-3 on Azure Linux 3.0
azl3 xorg-x11-server-Xwayland 24.1.6-4 on Azure Linux 3.0
cbl2 xorg-x11-server 1.20.10-16 on CBL Mariner 2.0
cbl2 xorg-x11-server 1.20.10-16 on CBL-Mariner 2.0

✅ Remediation

KBRelease Notes (Security Update) KBCBL-Mariner Releases (Security Update) — fixed build 24.1.6-4

🔗 References (2)

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-33999
referencehttps://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade