Description
Nov json-jwt version >= 0.5.0 && < 1.9.4 contains a CWE-347: Improper Verification of Cryptographic Signature vulnerability in Decryption of AES-GCM encrypted JSON Web Tokens that can result in Attacker can forge a authentication tag. This attack appear to be exploitable via network connectivity. This vulnerability appears to have been fixed in 1.9.4 and later.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | ruby-json-jwt | 1.9.4-1 | — |
| Debian 13 | ruby-json-jwt | 1.9.4-1 | — |
| Debian 12 | ruby-json-jwt | 1.9.4-1 | — |
| Debian 9 | ruby-json-jwt | 1.6.2-1+deb9u1 | DSA-4283-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | ruby-json-jwt | No fix yet | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| RubyGems | json-jwt | >= 0.5.1, < 1.9.4 | 1.9.4 | GHSA-mj4x-wcxf-hm8x |
Advisories 1
- DSA-4283-1 ruby-json-jwt - security update Debian Security (DSA / DLA) · Mar 9, 2026
References
- https://github.com/nov/json-jwt/pull/62
- DSA-4283 vendor-advisory