How severe is CVE-2017-18239?

CVE-2017-18239 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2017-18239 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-18239?

CVE-2017-18239 affects Authentikat-jwt Project Authentikat-jwt. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2017-18239?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2017-18239 published?

CVE-2017-18239 was published on 2018-03-18 and last updated on 2026-06-17.

CVE-2017-18239

CVE-2017-18239 is a critical-severity vulnerability in Authentikat-jwt Project Authentikat-jwt with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 5.0
EPSS exploit prediction: 2% (79th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Authentikat-jwt Project Authentikat-jwt
Published: 2018-03-18
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2017-18239?: 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.
How severe is CVE-2017-18239?: CVE-2017-18239 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2017-18239 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-18239?: CVE-2017-18239 affects Authentikat-jwt Project Authentikat-jwt. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2017-18239?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2017-18239 published?: CVE-2017-18239 was published on 2018-03-18 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:authentikat-jwt_project:authentikat-jwt:*:*:*:*:*:*:*:*