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GHSA-w67g-5rqw-f597 json

Gorilla WebSocket Uses Cryptographically Weak PRNG for WebSocket Mask Key

published 2mo ago modified 2mo ago also GO-2026-6278

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
—
no score, EPSS covers CVEs only
public exploits
0
none known

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

Patch / fix

  • go github.com/gorilla/websocket 1.5.3

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Affected packages

ecosystem package affected fixed in
go github.com/gorilla/websocket
<1.5.3
1.5.3

Classification

Weakness
  • CWE-338 Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.