GitHub Advisoryadvisory · crates.io

GHSA-434v-x5qv-pmh6 libcrux has All-Zero Key Generation Upon Catastrophic RNG Failure

HIGH Published 2026-03-26 Modified 2026-03-26 Official page ↗
Ecosystem
crates.io
Packages
libcrux-ed25519
Severity
High
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Weaknesses
CWE-1240, CWE-331, CWE-392
Reviewed
2026-03-26

Affected packages

• crates.io libcrux-ed25519: < 0.0.7 → fixed in 0.0.7

Description

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.

Related

Weakness · CWE (3)

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

References