A AegiFlow
MEDIUMCVSS 6.9

GHSA-w67g-5rqw-f597

Gorilla WebSocket Uses Cryptographically Weak PRNG for WebSocket Mask Key

Published
2026-08-24
Modified
2026-08-24
Sources
github-advisory

Summary

gorilla/websocket used `math/rand` (cryptographically weak pseudo-random number generator) to generate WebSocket frame mask keys prior to commit d67f4185. WebSocket masking keys MUST be unpredictable to prevent frame content injection attacks. math/rand produces deterministic output when seeded with a known value, enabling an attacker to predict or recover mask keys and inject content into WebSocket connections. **Type:** Use of Cryptographically Weak Pseudo-Random Number Generator **Fix:** Replaced math/rand with crypto/rand (commit d67f4185, released in v1.5.3) **Credit:** bounty-hunter v6.0 silent-fix detection

Affected packages

EcosystemPackageAffected versionsFixed versions
Gogithub.com/gorilla/websocket1.5.3

Remediation: Upgrade to 1.5.3 or later.

References

Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.