Vulnerability in Nearform Get-Jwks
CVE-2025-59936
get-jwks contains fetch utils for JWKS keys. In versions prior to 11.0.2, a vulnerability in get-jwks can lead to cache poisoning in the JWKS key-fetching mechanism. When the iss (issuer) claim is validated only after keys are retrieved from the cache, it is possible for cached keys from an unexpected issuer to be reused, resulting in a bypass of issuer validation. This design flaw enables a potential attack where a malicious actor crafts a pair of JWTs, the first one ensuring that a chosen public key is fetched and stored in the shared JWKS cache, and the second one leveraging that cached key to pass signature validation for a targeted iss value. The vulnerability will work only if the iss validation is done after the use of get-jwks for keys retrieval. This issue has been patched in version 11.0.2.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.4 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L.
EPSS exploit prediction
EPSS: 0.004 (32.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 32.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Nearform Get-Jwks — versions < 11.0.2
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2025-59936?
- CVE-2025-59936 is a critical-severity vulnerability in Nearform Get-Jwks, classified under Improper Encoding or Escaping of Output. CVSS score: 9.4/10. Published 2025-09-27.
- How severe is CVE-2025-59936?
- Critical severity. CVSS v3 base score is 9.4 out of 10.