High (7.8). EPSS 0.6% chance of exploitation in the next 30 days.
A flaw was found in xorg-x11-server before 1.20.9. An integer underflow in the X input extension protocol decoding in the X server may lead to arbitrary access of memory contents. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Severity
CVSS 3.1
7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
0.6% chance of exploitation in the next 30 days; higher than 50% of CVEs (scores of 2026-10-31)