CVE-2023-37303

Name: CVE-2023-37303
Creator: NVD / NIST
Published: 2023-06-30T17:15:09.617+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 0.80%

Last modified Jun 17, 2026

CVE-2023-37303 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. An issue was discovered in the CheckUser extension for MediaWiki through 1.39.3. In certain situations, an attempt to block a user fails after a temporary browser hang and a DBQueryDisconnectedError error message.. EPSS estimates a 0.80% chance of exploitation in the next 30 days.

Description

An issue was discovered in the CheckUser extension for MediaWiki through 1.39.3. In certain situations, an attempt to block a user fails after a temporary browser hang and a DBQueryDisconnectedError error message.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.80%

51.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-754

Affected Software

Vendor	Product	Versions
Mediawiki	Mediawiki	<= 1.39.3

References

https://gerrit.wikimedia.org/r/q/I10a9273c542576b3f7bb38de68dcd2aa41cfb1b0Vendor Advisory
https://phabricator.wikimedia.org/T338276Exploit, Issue Tracking, Patch, Vendor Advisory
https://gerrit.wikimedia.org/r/q/I10a9273c542576b3f7bb38de68dcd2aa41cfb1b0Vendor Advisory
https://phabricator.wikimedia.org/T338276Exploit, Issue Tracking, Patch, Vendor Advisory

Timeline

Published: Jun 30, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-37303?

How severe is CVE-2023-37303?

CVE-2023-37303 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.80% probability of exploitation in the next 30 days.

How do I fix CVE-2023-37303?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-37303?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST