Vulnerability Description
AnyCable is a realtime server for reliable two-way communication that supports any backend. Prior to 1.6.15, the Pusher-compatible REST API in pusher/http.go includes the caller-supplied body_md5 value in the HMAC input but does not calculate the digest of the received request body or compare it with the signed value. An attacker who obtains a legitimate signed POST request can retain its query parameters and auth_signature while replacing the body, causing Handler and handleEvents to accept and broadcast attacker-selected event content. The absence of an auth_timestamp freshness check also allows the captured signature to be replayed indefinitely. This can forge server-side events, modify application state, or deliver attacker-controlled messages to WebSocket clients within the signed request's application context. This issue is fixed in version 1.6.15.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/anycable/anycable/commit/d2cbadec792f038f4695c84a65c0d957b0fd
- https://github.com/anycable/anycable/releases/tag/v1.6.15
- https://github.com/anycable/anycable/security/advisories/GHSA-5p54-whvp-x327
- https://github.com/anycable/anycable/security/advisories/GHSA-5p54-whvp-x327
FAQ
What is CVE-2026-63405?
CVE-2026-63405 is a vulnerability with a CVSS score of 5.9 (MEDIUM). AnyCable is a realtime server for reliable two-way communication that supports any backend. Prior to 1.6.15, the Pusher-compatible REST API in pusher/http.go includes the caller-supplied body_md5 valu...
How severe is CVE-2026-63405?
CVE-2026-63405 has been rated MEDIUM with a CVSS base score of 5.9/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-63405?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.