Critical
Security advisory
A time-sensitive equality check on the JWT signature in the JsonWebToken.validate method in main/scala/authentikat/jwt/JsonWebToken.scala in authentikat-jwt (aka com.jason-goodwin/authentikat-jwt) version 0.4.5 and earlier allows the supplier of a JWT token to guess bit after bit of the signature by repeating validation requests.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2017-18239
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 09:55 UTC · Revision 1
Source evidence
A time-sensitive equality check on the JWT signature in the JsonWebToken.validate method in main/scala/authentikat/jwt/JsonWebToken.scala in authentikat-jwt (aka com.jason-goodwin/authentikat-jwt) version 0.4.5 and earlier allows the supplier of a JWT token to guess bit after bit of the signature by repeating validation requests.
osv:CVE-2017-18239
Complete source record
{
"id": "4fd6592acb5bb23c44dcf3d192ab5beabfb72f90f48fa8dcdc6700a6b8a57662",
"url": "https://osv.dev/vulnerability/CVE-2017-18239",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2017-18239",
"summary": "A time-sensitive equality check on the JWT signature in the JsonWebToken.validate method in main/scala/authentikat/jwt/JsonWebToken.scala in authentikat-jwt (aka com.jason-goodwin/authentikat-jwt) version 0.4.5 and earlier allows the supplier of a JWT token to guess bit after bit of the signature by repeating validation requests.",
"evidence": "osv:CVE-2017-18239",
"products": [],
"severity": "critical",
"structured": {
"id": "CVE-2017-18239",
"aliases": [
"CVE-2017-18239",
"GHSA-3rhm-67j6-42jq"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/jasongoodwin/authentikat-jwt",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "2d2fa0d40ac8f2f7aa7e9b070fa1a25eee082cb0"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"fixed": "2d2fa0d40ac8f2f7aa7e9b070fa1a25eee082cb0"
}
],
"source": "REFERENCES_COMMIT"
}
]
}
}
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2017-18239.json"
}
}
],
"modified": "2026-10-20T10:48:30.033763781Z",
"provider": "osv",
"references": [
"https://github.com/jasongoodwin/authentikat-jwt/issues/12",
"https://github.com/jasongoodwin/authentikat-jwt/pull/36",
"https://github.com/jasongoodwin/authentikat-jwt/commit/2d2fa0d40ac8f2f7aa7e9b070fa1a25eee082cb0"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:a:authentikat-jwt_project:authentikat-jwt:*:*:*:*:*:*:*:*"
],
"vendor_product": "authentikat-jwt_project:authentikat-jwt",
"extracted_events": [
{
"range": [
{
"last_affected": "0.4.5"
}
],
"source": "CPE_RANGE"
}
]
},
{
"extracted_events": [
{
"range": [
{
"last_affected": "0.4.5"
}
],
"source": "DESCRIPTION"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2017-18239",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 380313,
"published_at": "2018-03-18T03:29:00.213+00:00"
}