CVE-2026-89315 json
JwtClaims.MarshalJSON panics via reflect.StructOf when any untyped claim key is not a valid Go identifier suffix
published 2026-10-23 17 d ago modified 2026-11-02 7 d ago also EUVD-2026-108647
- cvss
- 6.9
- version 4.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 16%
- public exploits
- 0
- none known
Summary
`JwtClaims.MarshalJSON` built a Go struct at runtime with `reflect.StructOf`, synthesising a field named `"A" + claimName` for each untyped claim. `reflect.StructOf` **panics** when a field name is not a valid Go identifier, or when it duplicates another field. Both conditions are reachable from ordinary JWT claim names.
Patch / fix
- Eclipse Foundation Eclipse KeyPont - GOSE 1.0.0-rc4
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 7 d ago
Exploit prediction
0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N |
| CNA | 4.0 | 6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/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-248 Uncaught Exception
References
Sources
- CVE List CVE-2026-89315
- NVD CVE-2026-89315
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