matrix-js-sdk subject to impersonated messages due to permissive key forwarding

Description

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.

Recommendation

Update the matrix-js-sdk package to the latest compatible version. Followings are version details:

• Affected version(s): < 19.7.0
• Patched version(s): 19.7.0

References

• GHSA-6263-x97c-c4gg
• matrix.org
• security.gentoo.org
• CVE-2022-39249
• CWE-287
• CAPEC-310
• OWASP 2021-A6
• OWASP 2021-A7

Related Issues

• matrix-js-sdk has insufficient MXC URI validation which allows client-side path traversal - CVE-2024-50336
• matrix-js-sdk has insufficient validation when considering a room to be upgraded by another - CVE-2025-59160
• Mermaid does not properly sanitize architecture diagram iconText leading to XSS - CVE-2025-54880
• PDF.js vulnerable to arbitrary JavaScript execution upon opening a malicious PDF - CVE-2024-4367

Tags:

npm

matrix-js-sdk