CVE-2025-62666Network attack vector

Service interruption via unthrottled document builds

Published Oct 18, 2025 · Updated Oct 20, 2025

Resource exhaustion in Wikimedia Foundation CirrusSearch before 1.43 allows remote attackers to interrupt service through API requests. The cirrusbuilddoc query property invokes QueryBuildDocument to generate full search-index documents without the PoolCounter concurrency controls applied to ordinary searches. Unauthenticated access to the public MediaWiki API is sufficient, and repeated expensive document builds can exhaust server capacity and disrupt HTTP service.

CVSS severity6.9
Medium
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Resource exhaustion in Wikimedia Foundation CirrusSearch before 1.43 allows remote attackers to interrupt service through API requests. The cirrusbuilddoc query property invokes QueryBuildDocument to generate full search-index documents without the PoolCounter concurrency controls applied to ordinary searches. Unauthenticated access to the public MediaWiki API is sufficient, and repeated expensive document builds can exhaust server capacity and disrupt HTTP service.

The record

CVE
CVE-2025-62666
Published
Oct 18, 2025
Updated
Oct 20, 2025
Vendor
Wikimedia Foundation
Product
CirrusSearch
Classifications
CWE-770, CAPEC-469, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 18, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 20, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=master <1.43

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Wikimedia Foundation · CirrusSearchversion=master <1.43

Published CVSS scores

6.9Wikimedia FoundationCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
CAPEC-469HTTP DoS
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo