{"id":"CVE-2026-45056","title":"matrix-sdk-crypto is a no-network-IO implementation of a state machine that handles end-to-end encryption for Matrix clients","summary":"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…","severity":"medium","cvss":6.9,"cvssVector":"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","cwe":["CWE-290"],"vendor":"matrix-org","product":"matrix-rust-sdk","affected":["matrix-rust-sdk >= 0.12.0, < 0.16.1"],"published":"2026-09-11","updated":"2026-09-14","sourceUpdated":"2026-09-14T19:17:22.060","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-45056","references":[{"url":"https://github.com/matrix-org/matrix-rust-sdk/pull/6553","label":"security-advisories@github.com"},{"url":"https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1","label":"security-advisories@github.com"},{"url":"https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-wfq4-36m3-9g42","label":"security-advisories@github.com"},{"url":"https://rustsec.org/advisories/RUSTSEC-2026-0159.html","label":"security-advisories@github.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45056.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-45056"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-45056"}],"tags":["nvd","cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00234,"epssPercentile":0.14653,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-14T16:14:48.205206Z"},"cvssSource":"cna","scores":{"cna":6.9,"vendor":4.9},"ingestedAt":"2026-09-14T11:11:19.877Z","slug":"CVE-2026-45056","body":"## Overview\n\nmatrix-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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45056.json)","depth":"sunlit","depthScore":38,"depthScoreParts":{"impact":38,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":203181,"id":"CVE-2026-45056","ts":1789413244997,"field":"cvss","old":"4.9","new":"6.9"},{"seq":202809,"id":"CVE-2026-45056","ts":1789403726808,"field":"cvss","old":"6.9","new":"4.9"}]}