{"id":"CVE-2026-43946","aliases":["GHSA-fwcm-rqvw-j3p7"],"url":"https://o3.security/vulnerability/CVE-2026-43946","summary":"FUXA has an unauthenticated arbitrary tag value disclosure via /api/getTagValue","details":"### Summary\n An authorization bypass in the /api/getTagValue endpoint allows unauthenticated access to tag values when the referenced script does not exist.\n\n  ### Details\n  The issue is caused by the combination of these code paths:\n\n  - `server/api/apikeys/verify-api-or-token.js:45` sends requests without `x-api-key` to `authJwt.verifyToken(req, res, next)`.\n  - `server/api/jwt-helper.js:46-64` creates a signed guest token when no `x-access-token` is provided:\n    `if (!token) { token = getGuestToken(); }`\n    and then populates `req.userId` / `req.userGroups` from that guest token.\n  - `server/api/command/index.js:76-105` exposes `/api/getTagValue`.\n  - `server/runtime/scripts/index.js:106-111` returns `true` when the referenced script does not exist:\n    `if (!script) { return true; }`\n\n  As a result, an unauthenticated request reaches `/api/getTagValue` as `guest`, and the authorization check is bypassed because `isAuthorisedByScriptName()` returns `true` when `sourceScriptName` is omitted or does not match a real script. The endpoint then returns arbitrary tag values by ID.\n\n  ### PoC\n\nRequests to /api/getTagValue without authentication could succeed when the authorization logic evaluated a non-existent sourceScriptName as authorized.","published":"2026-07-21T21:27:29.248Z","modified":"2026-08-12T03:51:19.919470115Z","cvss":null,"epss":{"score":0.00542,"percentile":0.43023,"asOf":"2026-08-15"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"fuxa-server","fixedVersion":"1.3.1"}],"fix":{"url":"https://github.com/frangoteam/FUXA/commit/78534da61a91613712b44bb63c8d7da8c5df5ca4","label":"frangoteam/FUXA@78534da"},"references":[{"type":"WEB","url":"https://github.com/frangoteam/FUXA/releases/tag/v1.3.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43946.json"},{"type":"ADVISORY","url":"https://github.com/frangoteam/FUXA/security/advisories/GHSA-fwcm-rqvw-j3p7"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43946"},{"type":"FIX","url":"https://github.com/frangoteam/FUXA/commit/78534da61a91613712b44bb63c8d7da8c5df5ca4"},{"type":"FIX","url":"https://github.com/frangoteam/FUXA/pull/2260"},{"type":"PACKAGE","url":"https://github.com/frangoteam/FUXA"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:19.919470115Z"}}