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Fencer Vulns
medium 6.3

CVE-2026-89317 json

JwtVerifierImpl.Verify does not enforce the JWS `crit` header (RFC 7515 §4.1.11)

published 2026-10-23 17 d ago modified 2026-11-02 6 d ago also EUVD-2026-108649

cvss
6.3
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits
0
none known

Summary

gose parsed the JWS `crit` header into `JwsHeader.Crit` and then never read it. RFC 7515 §4.1.11 requires a recipient to reject a JWS whose listed critical extension parameters it does not understand. gose implements no header extensions, so every token carrying a non-empty `crit` should have been rejected — and none were.

Patch / fix

  • Eclipse Foundation Eclipse KeyPont - GOSE 1.0.0-rc4

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
6 d ago

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/eclipse-keypont/gose/security/advisories/GHSA-445r-fpvv-hgwc referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 6.3 CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
CNA 4.0 6.3 CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • Eclipse Foundation Eclipse KeyPont - GOSE

Classification

Weakness
  • CWE-20 Improper Input Validation
  • CWE-347 Improper Verification of Cryptographic Signature
  • CWE-1288 Improper Validation of Consistency within Input

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.