Vulnerability · Published Oct 27, 2026 · Assigned by VulnCheck

CVE-2026-116891SemanticMediaWiki 4.2.0 before 7.2.1 Reflected XSS via Special:FacetedSearch cstate

Medium 6.1

In plain English

A medium-severity cross-site scripting in SemanticMediaWiki from SemanticMediaWiki. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.1Medium

Exploit odds (30 days)0.2%top 93.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

SemanticMediaWiki from 4.2.0 before 7.2.1 contains a reflected cross-site scripting vulnerability that allows unauthenticated attackers to inject HTML via unescaped cstate parameters in Special:FacetedSearch. Attackers can craft URLs with q, a matching crc32 csum or filtered=1, and cstate values that break out of hidden input attributes to execute script in victims' browsers.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Packagist	mediawiki/semantic-media-wiki	7.2.1	GHSA-9rcc-pmj8-ffhr

Affected products (as reported)

Vendor	Product	Versions
SemanticMediaWiki	SemanticMediaWiki	4.2.0 – before 7.2.1

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

References

GitHub Security Advisory (GHSA-9rcc-pmj8-ffhr) vendor-advisory
VulnCheck Advisory: SemanticMediaWiki 4.2.0 before 7.2.1 Reflected XSS via Special:FacetedSearch cstate third-party-advisory