CVE-2026-89315
JwtClaims.MarshalJSON panics via reflect.StructOf when any untyped claim key is not a valid Go identifier suffix
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
JwtClaims.MarshalJSON panics via reflect.StructOf when any untyped claim key is not a valid Go identifier suffix
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.
- Record
CVE-2026-89315- CVSS 4.0
- 6.9 Medium
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 - Weakness
- CWE-248
- Updated
- 2026-11-02
EUVDEUVD-2026-108647
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.
- Record
EUVD-2026-108647- CVSS 4.0
- 6.9 Medium
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 - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-89315- CVSS 4.0
- 6.9 Medium
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 - Weakness
- CWE-248
- Updated
- 2026-11-02
OSV
JwtClaims.MarshalJSON panics via reflect.StructOf when any untyped claim key is not a valid Go identifier suffix
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.
- Record
CVE-2026-89315- CVSS 4.0
- 6.9 Medium
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 - Weakness
- CWE-248
- Updated
- 2026-11-04
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | OSV | |
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-89315 is a medium vulnerability (CVSS 6.9) in Eclipse Foundation Keypont - Gose, published October 23, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.25%, the 16th percentile. No source names a fixed version.