PatchTheCVECVE-2026-89315: `JwtClaims.MarshalJSON` built a Go struct at runtime with `reflect.StructOf`, synthesising a field named `"A"
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Routine
MEDIUM 6.9REMOTE
CVE-2026-89315 is a medium-severity flaw (CVSS 6.9) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
`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.
Why this priority
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 6.9 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.3% (top 84%) |
| CISA exploited list | No |
| Weakness | CWE-248 |
| Published | 2026-10-23 |
| Last modified | 2026-10-23 |
Publisher (CNA): Eclipse Foundation
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Fedora 46 · wasmedge · FIXED · 0.18.1-1.fc46 · FEDORA-2026-4c27216e39 · source
sudo dnf upgrade --advisory=FEDORA-2026-4c27216e39
Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.