{"id":"CVE-2026-45056","state":"PUBLISHED","title":"Matrix Rust SDK: Sender-binding gaps in to-device and room-key attribution","description":"matrix-sdk-crypto is a no-network-IO implementation of a state machine that handles end-to-end encryption for Matrix clients. Starting in version 0.12.0 and prior to version 0.17.0, the matrix-sdk-crypto crate was missing a check for the user ID when decrypting an Olm-encrypted event containing the `sender_device_keys` property. This could be exploited to forge an encrypted to-device event, but only if the attacker colludes with the homeserver operator. This issue is fixed in matrix-sdk-crypto 0.17.0. There are no known workarounds for the issue.","publishedAt":"2026-09-11T21:13:56.332Z","updatedAt":"2026-09-14T18:17:31.910Z","severity":{"score":6.9,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["matrix-org matrix-rust-sdk"],"affected":[{"vendor":"matrix-org","product":"matrix-rust-sdk","versions":[{"version":">= 0.12.0, < 0.16.1","status":"affected"}]}],"references":["https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-wfq4-36m3-9g42","https://github.com/matrix-org/matrix-rust-sdk/pull/6553","https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1","https://rustsec.org/advisories/RUSTSEC-2026-0159.html"],"weaknesses":["CWE-290"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/45xxx/CVE-2026-45056.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-45056","state":"PUBLISHED","datePublished":"2026-09-11T21:13:56.332Z","dateUpdated":"2026-09-14T18:17:31.910Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-05-08T18:07:27.342Z"},"containers":{"cna":{"title":"Matrix Rust SDK: Sender-binding gaps in to-device and room-key attribution","descriptions":[{"lang":"en","value":"matrix-sdk-crypto is a no-network-IO implementation of a state machine that handles end-to-end encryption for Matrix clients. Starting in version 0.12.0 and prior to version 0.17.0, the matrix-sdk-crypto crate was missing a check for the user ID when decrypting an Olm-encrypted event containing the `sender_device_keys` property. This could be exploited to forge an encrypted to-device event, but only if the attacker colludes with the homeserver operator. This issue is fixed in matrix-sdk-crypto 0.17.0. There are no known workarounds for the issue."}],"affected":[{"vendor":"matrix-org","product":"matrix-rust-sdk","versions":[{"version":">= 0.12.0, < 0.16.1","status":"affected"}]}],"references":[{"url":"https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-wfq4-36m3-9g42","name":"https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-wfq4-36m3-9g42","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/matrix-org/matrix-rust-sdk/pull/6553","name":"https://github.com/matrix-org/matrix-rust-sdk/pull/6553","tags":["x_refsource_MISC"]},{"url":"https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1","name":"https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1","tags":["x_refsource_MISC"]},{"url":"https://rustsec.org/advisories/RUSTSEC-2026-0159.html","name":"https://rustsec.org/advisories/RUSTSEC-2026-0159.html","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"HIGH","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":6.9,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-290","lang":"en","description":"CWE-290: Authentication Bypass by Spoofing","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-11T21:13:56.332Z"},"source":{"advisory":"GHSA-wfq4-36m3-9g42","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-14T16:14:48.205206Z","id":"CVE-2026-45056","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-14T18:17:31.910Z"}}]}}}