{"id":"CVE-2026-45057","sourceIdentifier":"security-advisories@github.com","published":"2026-09-11T21:17:09.517","lastModified":"2026-09-30T19:57:08.043","vulnStatus":"Deferred","cveTags":[],"descriptions":[{"lang":"en","value":"matrix-sdk-ui provides GUI-centric utilities on top of matrix-rust-sdk. The message edit validation logic in the  `matrix-sdk-ui` crate prior to 0.17.0 is missing a check: when replacing an encrypted event, the replacement event itself is not required to be encrypted. This enables a malicious homeserver administrators (or actors with equivalent power) to impersonate or spoof messages as if they were sent by a victim user. `matrix-sdk-ui` 0.17.0 fixes the message edit validation logic to align with the algorithm for replacement events[^1] described in the Matrix specification. No known workarounds are available."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"matrix-org","product":"matrix-sdk-ui","versions":[{"version":"< 0.16.1","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N","baseScore":4.9,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"HIGH","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE"},"exploitabilityScore":1.2,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-09-14T16:16:05.439558Z","id":"CVE-2026-45057","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-345"}]}],"references":[{"url":"https://github.com/matrix-org/matrix-rust-sdk/pull/6454","source":"security-advisories@github.com"},{"url":"https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1","source":"security-advisories@github.com"},{"url":"https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-h97m-27fx-42rx","source":"security-advisories@github.com"},{"url":"https://rustsec.org/advisories/RUSTSEC-2026-0158.html","source":"security-advisories@github.com"}]}