CVE-2026-63405
AnyCable is a realtime server for reliable two-way communication that supports any backend. Prior to 1.6.15, the Pusher-compatible REST API
CVSS
5.9
Medium
EPSS
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KEV
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Exploit Today
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0-100
Published: Sep 18, 2026 · Last modified: Sep 18, 2026 · CWE-345
Not enough EPSS history yet.
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.
- github.comhttps://github.com/anycable/anycable/commit/d2cbadec792f038f4695c84a65c0d957b0fde72c
- github.comhttps://github.com/anycable/anycable/releases/tag/v1.6.15
- github.comhttps://github.com/anycable/anycable/security/advisories/GHSA-5p54-whvp-x327
- github.comhttps://github.com/anycable/anycable/security/advisories/GHSA-5p54-whvp-x327