CVE-2020-14346

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-09-15 · updated 2026-06-17
Weakness: CWE-191

Description

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.

Affected products

Canonical Ubuntu Linux: 14.04
Red Hat Enterprise Linux: 6.0, 7.0, 8.0
xorg-x11-server: before 1.20.9 — fixed in 1.20.9

How to fix

Upgrade to a fixed version: xorg-x11-server 1.20.9. Check the vendor advisory for mitigations.

References

https://bugzilla.redhat.com/show_bug.cgi?id=1862246
https://lists.x.org/archives/xorg-announce/2020-August/003058.html
https://security.gentoo.org/glsa/202012-01
https://usn.ubuntu.com/4488-2/
https://www.zerodayinitiative.com/advisories/ZDI-20-1417/
https://bugzilla.redhat.com/show_bug.cgi?id=1862246
https://lists.x.org/archives/xorg-announce/2020-August/003058.html
https://security.gentoo.org/glsa/202012-01
https://usn.ubuntu.com/4488-2/
https://www.zerodayinitiative.com/advisories/ZDI-20-1417/

Get alerted when CVE-2020-14346 or the next vulnerability affects your stack