Unauthenticated service degradation via exponential regex matching
Published Jan 30, 2026 · Updated Jan 30, 2026
Regular expression denial of service in Wikimedia Foundation DiscussionTools 1.43 and 1.44 allows remote attackers to exhaust server CPU. The post-cache HTML transformation applies backtracking regular expressions to attacker-influenced discussion-page markup, so crafted content triggers exponential matching. No authentication or user interaction is required; processing the crafted content can monopolize request workers and degrade the wiki service.
Summary
What happened
Regular expression denial of service in Wikimedia Foundation DiscussionTools 1.43 and 1.44 allows remote attackers to exhaust server CPU. The post-cache HTML transformation applies backtracking regular expressions to attacker-influenced discussion-page markup, so crafted content triggers exponential matching. No authentication or user interaction is required; processing the crafted content can monopolize request workers and degrade the wiki service.
The record
- CVE
- CVE-2025-11175
- Published
- Jan 30, 2026
- Updated
- Jan 30, 2026
- Vendor
- Wikimedia Foundation
- Product
- DiscussionTools
- Classifications
- CWE-917, CAPEC-492, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 30, 2026CVE publishedPublication date reported by the CVE source.
- Jan 30, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.43
- Affected versionversion=1.44
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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