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Fencer Intel
medium 6.3

CVE-2026-89317 json

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

published 2mo ago modified 9d ago also EUVD-2026-108649 , GHSA-445r-fpvv-hgwc

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository eclipse-keypont/gose. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

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

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
9d ago

Exploit prediction

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

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 Intel 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.

The maintainers of eclipse-keypont/gose published their own advisory on GitHub. Reviewed sources take precedence over it.