CVE-2026-126564: SemanticMediaWiki · Cross-site Scripting
Affects SemanticMediaWikiSource CVE Database V5
Not known to be exploited · CVSS 5.1 Medium : upgrade to 7.4.1 when convenient.
Data as of 11 Nov 2026, 02:49 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 5.1 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 5.4 |
- Patch
- Available – fixed in 7.4.1
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 11 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Upgrade SemanticMediaWiki to 7.4.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| SemanticMediaWikiSemanticMediaWiki | Affected
| Fixed in
|
PackagistSemanticMediaWikipkg:composer/SemanticMediaWikiOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in Semantic MediaWiki version 7.4.1. Users should upgrade to version 7.4.1 or later to remediate this vulnerability. Until upgrading, restrict page-edit rights to trusted users only to reduce the risk of exploitation.
Description
Semantic MediaWiki versions from 2.5.0 up to but not including 7.4.1 contain a stored cross-site scripting (XSS) vulnerability. This flaw exists in the ValueFormatter::getFormattedSubject() function, which improperly renders property label segments after a literal non-breaking space ( ) as unescaped markup. Users with page-edit rights can exploit this by setting a preferred property label containing a malicious img onerror payload. This payload executes when any user, including administrators, views the Special:Browse page or accesses the smwbrowse API.
References
- github.com/SemanticMediaWiki/SemanticMediaWiki/security/advisories/GHSA-mc5x-2j7v-x8hp (opens in a new tab)
- github.com/SemanticMediaWiki/SemanticMediaWiki/commit/c9bf9f25549bb2f5eab916339b267a1732002c4c (opens in a new tab)
- github.com/SemanticMediaWiki/SemanticMediaWiki/releases/tag/7.4.1 (opens in a new tab)
- github.com/SemanticMediaWiki/SemanticMediaWiki/blob/7.4.0/src/MediaWiki/Specials/Browse/ValueFormatter.php (opens in a new tab)
- vulncheck.com/advisories/semantic-mediawiki-2.5.0-before-7.4.1-stored-xss-via-special-browse-factbox-title (opens in a new tab)