CVE-2026-63405 Details
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.
A vulnerability exists in AnyCable's Pusher-compatible REST API prior to version 1.6.15. The API includes a caller-supplied 'body_md5' value in the HMAC signature calculation but fails to verify the actual MD5 digest of the received request body. This oversight allows an attacker to replace the body of a legitimate signed POST request while retaining the original query parameters and authentication signature. Additionally, the lack of a freshness check for the 'auth_timestamp' parameter enables indefinite replay of the captured signature. Exploiting this vulnerability can lead to unauthorized events being broadcasted to WebSocket clients, potentially altering application state or delivering phishing messages, all within the context of the signed request's application.
Users can upgrade to AnyCable version 1.6.15 or later, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Sep 18, 2026CISA-ADP
Assessed Sep 18, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/anycable/anycable/security/advisories/GHSA-5p54-whvp-x327 | CISA-ADP | AdvisoryExploitRemedyVendor |
| https://github.com/anycable/anycable/commit/d2cbadec792f038f4695c84a65c0d957b0fde72c | [email protected] | Source CodeVendor |
| https://github.com/anycable/anycable/releases/tag/v1.6.15 | [email protected] | Release NotesVendor |
| https://github.com/anycable/anycable/security/advisories/GHSA-5p54-whvp-x327 | [email protected] | AdvisoryExploitRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-345 | Insufficient Verification of Data Authenticity | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| AnyCable | <= 1.6.14 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 18, 2026 | CVE Modified | CISA-ADP |
| Sep 18, 2026 | New CVE Received | [email protected] |