{"id":"CVE-2026-77616","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-77616","generatedAt":"2026-10-28T02:20:00.302Z","title":"The token is decoded by `CursorEncoder`, which is an **unsigned** base64url-encoded JSON blob, so its contents are fully attacker-controlled.","description":"Semantic MediaWiki is a free, open-source extension to MediaWiki that lets users store and query data within the wiki's pages. In versions 7.0.0 through 7.1.0, `Special:Ask` accepts a `cursor` query parameter for keyset pagination (added in 7.0.0). The token is decoded by `CursorEncoder`, which is an **unsigned** base64url-encoded JSON blob, so its contents are fully attacker-controlled. When the cursor's sort anchor does not match the request's `sort=` / `order=`, `QueryCreator::applyCursorIfRequested()` builds an error message by interpolating the attacker-controlled `sort_prop` / `sort_order` values into a raw string via `Query::addErrors()`. Unlike SMW's message-key errors, this raw string bypasses the message layer's sanitization (`ProcessingErrorMsgHandler::normalizeAndDecodeMessages()` passes a non-key, non-encoded string through unchanged). `ErrorWidget::queryError()` then assembles the errors and passes them to `Html::errorBox()`, whose first argument is emitted as raw HTML. The result is a reflected cross-site scripting vulnerability: a crafted `cursor` token containing markup in `sort_prop` (or `sort_order`) executes script in the victim's browser on the wiki origin. No authentication or special permission is required. The payload is delivered via a crafted link. Version 7.2.0 contains a fix.","published":"2026-09-18T17:17:02.000Z","lastModified":"2026-09-24T21:22:20.000Z","status":"Awaiting Analysis","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":6.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},"cwe":["CWE-79"],"affected":[],"epss":{"score":0.0033,"percentile":0.25894,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.33%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/SemanticMediaWiki/SemanticMediaWiki/releases/tag/7.2.0","source":"security-advisories@github.com"},{"url":"https://github.com/SemanticMediaWiki/SemanticMediaWiki/security/advisories/GHSA-cx86-7xwp-w9wf","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-77616","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}