Vulnerability · Published Oct 23, 2026 · Assigned by eclipse
CVE-2026-89315JwtClaims.MarshalJSON panics via reflect.StructOf when any untyped claim key is not a valid Go identifier suffix
Medium 6.9
In plain English
A medium-severity security flaw in Eclipse KeyPont - GOSE from Eclipse Foundation. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 17% of all known vulnerabilities).
Severity (CVSS 4.0)6.9Medium
Exploit odds (30 days)0.3%top 83.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
`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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Eclipse Foundation | Eclipse KeyPont - GOSE | 0.7.3 – through 0.13.0-rc1 |
| Eclipse Foundation | Eclipse KeyPont - GOSE | 0 – before 1.0.0-rc4 |
Weakness: CWE-248 · Vector: 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