{"cve":"CVE-2022-39249","nvd":{"published":"2022-09-28T20:15:16.127","modified":"2026-06-17T04:57:59.723","status":"Modified","description":"Matrix Javascript SDK is the Matrix Client-Server SDK for JavaScript. Prior to version 19.7.0, an attacker cooperating with a malicious homeserver can construct messages appearing to have come from another person. Such messages will be marked with a grey shield on some platforms, but this may be missing in others. This attack is possible due to the matrix-js-sdk implementing a too permissive key forwarding strategy on the receiving end. Starting with version 19.7.0, the default policy for accepting key forwards has been made more strict in the matrix-js-sdk. matrix-js-sdk will now only accept forwarded keys in response to previously issued requests and only from own, verified devices. The SDK now sets a `trusted` flag on the decrypted message upon decryption, based on whether the key used to decrypt the message was received from a trusted source. Clients need to ensure that messages decrypted with a key with `trusted = false` are decorated appropriately, for example, by showing a warning for such messages. This attack requires coordination between a malicious homeserver and an attacker, and those who trust your homeservers do not need a workaround.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5},"cwes":["CWE-287","CWE-322"],"references":["https://github.com/matrix-org/matrix-js-sdk/commit/a587d7c36026fe1fcf93dfff63588abee359be76","https://github.com/matrix-org/matrix-js-sdk/releases/tag/v19.7.0","https://github.com/matrix-org/matrix-js-sdk/security/advisories/GHSA-6263-x97c-c4gg","https://github.com/matrix-org/matrix-spec-proposals/pull/3061","https://matrix.org/blog/2022/09/28/upgrade-now-to-address-encryption-vulns-in-matrix-sdks-and-clients"],"products":["matrix:javascript_sdk"],"source":"nvd","synced_at":"2026-10-19T21:36:05.460296998+00:00"},"epss":{"cve":"CVE-2022-39249","score":0.01276,"percentile":0.69944,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-6263-x97c-c4gg","url":"https://osv.dev/vulnerability/GHSA-6263-x97c-c4gg","summary":"matrix-js-sdk subject to impersonated messages due to permissive key forwarding","modified":"2023-11-08T04:10:16.571099Z","packages":[{"ecosystem":"npm","name":"matrix-js-sdk","purl":"pkg:npm/matrix-js-sdk","ranges":["<19.7.0"],"fixed":["19.7.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}