{"id":"CVE-2022-36009","aliases":["GHSA-grvv-h2f9-7v9c","GO-2022-0952"],"url":"https://o3.security/vulnerability/CVE-2022-36009","summary":"Incorrect parsing of access level in gomatrixserverlib and dendrite","details":"gomatrixserverlib is a Go library for matrix protocol federation. Dendrite is a Matrix homeserver written in Go, an alternative to Synapse. The power level parsing within gomatrixserverlib was failing to parse the `\"events_default\"` key of the `m.room.power_levels` event, defaulting the event default power level to zero in all cases. Power levels are the matrix terminology for user access level. In rooms where the `\"events_default\"` power level had been changed, this could result in events either being incorrectly authorised or rejected by Dendrite servers. gomatrixserverlib contains a fix as of commit `723fd49` and Dendrite 0.9.3 has been updated accordingly. Matrix rooms where the `\"events_default\"` power level has not been changed from the default of zero are not vulnerable. Users are advised to upgrade. There are no known workarounds for this issue.","published":"2022-08-19T20:35:09Z","modified":"2026-08-12T03:51:32.757200687Z","cvss":{"score":5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Go","name":"github.com/matrix-org/dendrite","fixedVersion":"0.9.3"},{"ecosystem":"Go","name":"github.com/matrix-org/gomatrixserverlib","fixedVersion":"0.0.0-20220815091947-723fd495dde8"}],"fix":{"url":"https://github.com/matrix-org/gomatrixserverlib/commit/723fd495dde835d078b9f2074b6b62c06dea4575","label":"matrix-org/gomatrixserverlib@723fd49"},"references":[{"type":"WEB","url":"https://matrix.org/docs/guides/moderation/#power-levels"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/36xxx/CVE-2022-36009.json"},{"type":"ADVISORY","url":"https://github.com/matrix-org/gomatrixserverlib/security/advisories/GHSA-grvv-h2f9-7v9c"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-36009"},{"type":"FIX","url":"https://github.com/matrix-org/gomatrixserverlib/commit/723fd495dde835d078b9f2074b6b62c06dea4575"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:32.757200687Z"}}