GHSA-434V-X5QV-PMH6
Vulnerability from github – Published: 2026-03-26 17:58 – Updated: 2026-03-26 17:58The 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.
{
"affected": [
{
"package": {
"ecosystem": "crates.io",
"name": "libcrux-ed25519"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.0.7"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-1240",
"CWE-331",
"CWE-392"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-26T17:58:55Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "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.\n\n## Impact\nThis 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.\n\n## Mitigation\nInstead 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.",
"id": "GHSA-434v-x5qv-pmh6",
"modified": "2026-03-26T17:58:55Z",
"published": "2026-03-26T17:58:55Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/cryspen/libcrux/pull/1349"
},
{
"type": "PACKAGE",
"url": "https://github.com/cryspen/libcrux"
},
{
"type": "WEB",
"url": "https://rustsec.org/advisories/RUSTSEC-2026-0075.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "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",
"type": "CVSS_V4"
}
],
"summary": "libcrux has All-Zero Key Generation Upon Catastrophic RNG Failure"
}
Sightings
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