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CVE-2025-26595

high

A buffer overflow flaw was found in X.Org and Xwayland.

Vendor / product: Tigervnc — tigervnc

A buffer overflow flaw was found in X.Org and Xwayland. The code in XkbVModMaskText() allocates a fixed-sized buffer on the stack and copies the names of the virtual modifiers to that buffer. The code fails to check the bounds of the buffer and would copy the data regardless of the size.

CVSS
7.8
7.8 (CVSS v3.1)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity source: NVD CVSS v3.1 (nvd@nist.gov)
Timeline (UTC)
Published: 2025-02-25 16:15
Modified: 2026-11-04 22:17
NVD status: Modified
Last synced 3 hours ago
Verified against the source API 2026-11-04 22:37 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

tigervnc / tigervnc all versions
x.org / x_server <21.1.16
x.org / xwayland <24.1.6
redhat / enterprise_linux 7.0, 8.0, 9.0

Weakness classification (CWE)

CWE-121 CWE-787

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

No vendor advisory or patch reference tagged by NVD. Check the references below.

References

Data sources

NVD CVE API 2.0 — fetched 2026-11-04 22:37 UTC · record ↗

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CVE-2025-26601CVE-2025-26600CVE-2025-26599CVE-2025-26598CVE-2025-26597