Integer overflow in X.org Xwayland

CVE-2025-49179

A flaw was found in the X Record extension. The RecordSanityCheckRegisterClients function does not check for an integer overflow when computing request length, which allows a client to bypass length checks.

Vulnerability class: Integer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H.

EPSS exploit prediction

EPSS: 0.003 (23.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 24th percentile — 23.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-49179: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-49179?
CVE-2025-49179 is a high-severity vulnerability in X.org Xwayland, classified under Integer Overflow or Wraparound. CVSS score: 7.3/10. Published 2025-06-17.
How severe is CVE-2025-49179?
High severity. CVSS v3 base score is 7.3 out of 10.