What is CVE-2023-22912?

CVE-2023-22912 is a medium-severity vulnerability in MediaWiki, classified under Use of Insufficiently Random Values. CVSS score: 5.3/10. Published 2023-01-20.

How severe is CVE-2023-22912?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in MediaWiki

CVE-2023-22912

An issue was discovered in MediaWiki before 1.35.9, 1.36.x through 1.38.x before 1.38.5, and 1.39.x before 1.39.1. CheckUser TokenManager insecurely uses AES-CTR encryption with a repeated (aka re-used) nonce, allowing an adversary to decrypt.

Published 2023-01-20 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (30.4th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 30.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

MediaWiki — versions 1.39.0

Weakness classification (CWE)

CWE-330 — Use of Insufficiently Random Values

References

phabricator.wikimedia.org/T315123 (Exploit, Patch, Issue Tracking, Vendor Advisory)

Frequently asked questions

What is CVE-2023-22912?: CVE-2023-22912 is a medium-severity vulnerability in MediaWiki, classified under Use of Insufficiently Random Values. CVSS score: 5.3/10. Published 2023-01-20.
How severe is CVE-2023-22912?: Medium severity. CVSS v3 base score is 5.3 out of 10.