CVE-2026-77609: Mediawiki/semantic media wiki URIResolver Vulnerability

MODERATE
Advisory Identifier: GHSA-hw3m-8j5x-94ff
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CVSS 6.1
CWE-601
Published
Advisory Summary

CVE-2026-77609 is a MODERATE (CVSS 6.1) uriresolver vulnerability (CWE-601: URL Redirection to Untrusted Site ('Open Redirect')) affecting Mediawiki/semantic media wiki libraries in the Packagist ecosystem. The issue involves uriresolver. Remediation is available by upgrading affected packages to version 7.2.0.

CVE-2026-77609 at a Glance

CVE Identifier CVE-2026-77609
GHSA Identifier GHSA-hw3m-8j5x-94ff
Severity MODERATE
CVSS v3.1 Base Score 6.1
CWE Classification CWE-601: URL Redirection to Untrusted Site ('Open Redirect')
Affected Product Mediawiki/semantic media wiki
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 6.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Changed (S:C)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-77609

To remediate this vulnerability, upgrade all affected Mediawiki/semantic media wiki dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

mediawiki/semantic-media-wiki fixed: 7.2.0 
Upgrade mediawiki/semantic-media-wiki to 7.2.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for mediawiki/semantic-media-wiki

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-77609, inspect your project dependencies for Mediawiki/semantic media wiki:

inspect dependencies for mediawiki/semantic-media-wiki

Analyze the terminal output to locate any version of Mediawiki/semantic media wiki in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 7.2.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-601: URL Redirection to Untrusted Site ('Open Redirect'), where the web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect. In Mediawiki/semantic media wiki, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

#### Failure mode `Special:URIResolver` resolves its user-controlled subpage to a MediaWiki title and issues an HTTP 303 redirect to `$title->getFullURL()` without validating the resolved target. A crafted subpage can make that target point off-host: an interwiki prefix redirects to the foreign wiki (for example `Special:URIResolver/mw-3AFoo`, which decodes to `mw:Foo`, redirects to `https://www.mediawiki.org/wiki/Foo`), and where the resolved URL carries an authority the target can even embed `user:pass@host` credentials. The result is an open redirect to an attacker-influenced host, usable for phishing from a trusted wiki URL. #### Remediation - The resolved target URL is parsed and compared against the current host at the redirect sink. - The redirect is rejected (bad-title error page) when a user or pass component is present, or when the host does not match the current host. #### Maintenance note Redirect code must validate the final target URL, not just the input path. Host comparison belongs at the redirect sink: each sink (special page, entry point) must validate its own target rather than relying on upstream normalisation.

CVE-2026-77609 Affected Mediawiki/semantic media wiki Versions

1 component(s)
Fixed Versions:
7.2.0
Product / Package Ecosystem Affected Versions Fixed Version
mediawiki/semantic-media-wiki
 Packagist
< 7.2.0
7.2.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/SemanticMediaWiki/SemanticMediaWiki/security/advisories/GHSA-hw3m-8j5x-94ff
Mediawiki/semantic media wiki Source Repository REPOSITORY
https://github.com/SemanticMediaWiki/SemanticMediaWiki
Mediawiki/semantic media wiki Release RELEASE
https://github.com/SemanticMediaWiki/SemanticMediaWiki/releases/tag/7.2.0

Frequently Asked Questions

What is CVE-2026-77609?
CVE-2026-77609 is a security vulnerability in Mediawiki/semantic media wiki involving URIResolver under CWE-601: URL Redirection to Untrusted Site ('Open Redirect').
Which Mediawiki/semantic media wiki versions are affected?
Affected versions include releases prior to 7.2.0 across affected packages: mediawiki/semantic-media-wiki.
What version fixes CVE-2026-77609?
Upgrading to 7.2.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is mediawiki/semantic-media-wiki affected?
Yes, mediawiki/semantic-media-wiki is affected in releases prior to 7.2.0. Upgrade your dependency to 7.2.0 or later.
What is the CVSS score of CVE-2026-77609?
CVE-2026-77609 has a CVSS v3.1 base score of 6.1 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2026-77609?
CVE-2026-77609 is classified under CWE-601: URL Redirection to Untrusted Site ('Open Redirect') (The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect.).
How can I check Packagist dependencies for CVE-2026-77609?
Run the dependency tree command: 'inspect dependencies for mediawiki/semantic-media-wiki'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-hw3m-8j5x-94ff",
  "modified" : "2026-09-18T16:51:25Z",
  "published" : "2026-09-18T16:51:25Z",
  "aliases" : [ "CVE-2026-77609" ],
  "summary" : "Semantic MediaWiki has an open redirect in Special:URIResolver",
  "details" : "#### Failure mode\n\n`Special:URIResolver` resolves its user-controlled subpage to a MediaWiki title and issues an HTTP 303 redirect to `$title->getFullURL()` without validating the resolved target. A crafted subpage can make that target point off-host: an interwiki prefix redirects to the foreign wiki (for example `Special:URIResolver/mw-3AFoo`, which decodes to `mw:Foo`, redirects to `https://www.mediawiki.org/wiki/Foo`), and where the resolved URL carries an authority the target can even embed `user:pass@host` credentials. The result is an open redirect to an attacker-influenced host, usable for phishing from a trusted wiki URL.\n\n#### Remediation\n\n- The resolved target URL is parsed and compared against the current host at the redirect sink.\n- The redirect is rejected (bad-title error page) when a user or pass component is present, or when the host does not match the current host.\n\n#### Maintenance note\n\nRedirect code must validate the final target URL, not just the input path. Host comparison belongs at the redirect sink: each sink (special page, entry point) must validate its own target rather than relying on upstream normalisation.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "mediawiki/semantic-media-wiki"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "7.2.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 7.1.0"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/SemanticMediaWiki/SemanticMediaWiki/security/advisories/GHSA-hw3m-8j5x-94ff"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/SemanticMediaWiki/SemanticMediaWiki"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/SemanticMediaWiki/SemanticMediaWiki/releases/tag/7.2.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-601" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-18T16:51:25Z",
    "nvd_published_at" : null
  }
}