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high —

GHSA-434v-x5qv-pmh6 json

libcrux has All-Zero Key Generation Upon Catastrophic RNG Failure

published 8mo ago modified 7mo ago also RUSTSEC-2026-0075

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

The libcrux-ed25519 key generation samples Ed25519 secret keys from a provided CSPRNG in a loop for up to 100 attempts until a non-zero key is found. If a non-zero key could not be sampled within 100 attempts the key generation function would silently continue with an all-zero buffer as the secret key.

## Impact This bug only occurs in the event of a catastrophic failure of the CSPRNG, but would allow anyone to forge signatures under the resulting static signing key.

## Mitigation Instead of silently continuing with an all-zero signing key, starting from version `0.0.7` key generation will error in the case of 100 failed attempts at sampling a valid key.

Patch / fix

  • crates.io libcrux-ed25519 0.0.7

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Affected packages

ecosystem package affected fixed in
crates.io libcrux-ed25519
<0.0.7
>=0.0.0-0, <0.0.7
0.0.7

Classification

Weakness
  • CWE-1240 Use of a Cryptographic Primitive with a Risky Implementation
  • CWE-331 Insufficient Entropy
  • CWE-392 Missing Report of Error Condition

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.