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Semantic MediaWiki search lets attackers exhaust CPU via long terms

Priority HIGH 77CWE-407Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-407.

Summary

Semantic MediaWiki from 3.0.0 before 7.3.1 contains an algorithmic complexity flaw in TermParser::normalize_compact_form() (CWE-407) that causes quadratic CPU consumption. An unauthenticated remote attacker can send crafted search queries to Special:Search, exhausting PHP search workers when the extended search engine is enabled. A public exploit is linked in the references.

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

Description from the CNA

Semantic MediaWiki from 3.0.0 before 7.3.1 contains an algorithmic complexity vulnerability in TermParser::normalize_compact_form() that allows unauthenticated attackers to cause quadratic CPU consumption. Attackers can submit long search terms with many distinct in:(...) or has:(...) expressions to Special:Search to exhaust PHP search workers when the extended search engine is enabled.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00374 31st percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed SemanticMediaWiki (SemanticMediaWiki): 7.3.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
SemanticMediaWikiSemanticMediaWiki3.0.0 to before 7.3.17.3.1Patch availableCNA
  • SemanticMediaWiki VendorSemanticMediaWiki Affected 3.0.0 to before 7.3.1 Fixed in 7.3.1 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:semantic-mediawiki:semantic_mediawiki:*:*:*:*:*:mediawiki:*:*3.0.0 to before 7.3.1VulnerableSemanticMediaWiki
  • cpe:2.3:a:semantic-mediawiki:semantic_mediawiki:*:*:*:*:*:mediawiki:*:* Versions 3.0.0 to before 7.3.1 Vulnerable ·SemanticMediaWiki

Remediation

Upgrade Semantic MediaWiki to version 7.3.1, the fixed version for the affected range from 3.0.0 before 7.3.1.

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

  • Fix · CNA SemanticMediaWiki (SemanticMediaWiki) Fixed in 7.3.1

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    SemanticMediaWiki 7.3.1

    20 records Highest priority Priority HIGH 4 HIGH, 13 MEDIUM, 3 LOW

    Other records, highest priority first

    • TI-2026-81081 Resource exhaustion in Semantic MediaWiki via #set_recurring_eventPriority HIGH 77
    • TI-2026-81075 Uncontrolled recursion in Semantic MediaWiki via Special:AskPriority HIGH 77
    • TI-2026-81077 Missing authorization in Semantic MediaWiki smwtask APIPriority HIGH 70

Timeline

  1. 2026-10-27 Threatist record created from CVE-2026-116872
  2. 2026-10-27 Alias added: GHSA-22p9-pjfx-9wj2
  3. 2026-10-28 Priority changed: MEDIUM → LOW
  4. 2026-10-31 CISA SSVC decision points changed
  5. 2026-10-31 Priority changed: LOW → HIGH

References

  • TI-2026-81081 Resource exhaustion in Semantic MediaWiki via #set_recurring_event CVSS 4.0HIGH 8.7
  • TI-2026-81075 Uncontrolled recursion in Semantic MediaWiki via Special:Ask CVSS 4.0HIGH 8.7
  • TI-2026-81077 Missing authorization in Semantic MediaWiki smwtask API CVSS 4.0MEDIUM 6.9
  • TI-2026-81084 Cross-site request forgery in Semantic MediaWiki SMWAdmin page CVSS 4.0HIGH 7.1
  • TI-2026-81083 Missing authorization in Semantic MediaWiki smwtask update task CVSS 4.0MEDIUM 6.9
  • TI-2026-81080 Missing authorization in Semantic MediaWiki lets editors lock pages CVSS 4.0HIGH 7.1
See all 22 →

Sources