Description
The json-jwt (aka JSON::JWT) gem 1.16.3 for Ruby sometimes allows bypass of identity checks via a sign/encryption confusion attack. For example, JWE can sometimes be used to bypass JSON::JWT.decode.
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.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | ruby-json-jwt | No fix yet | — |
| Ubuntu 26.04 LTS | ruby-json-jwt | No fix yet | — |
| Ubuntu 25.10 | ruby-json-jwt | No fix yet | — |
| Ubuntu 24.04 LTS | ruby-json-jwt | No fix yet | — |
| Ubuntu 22.04 LTS | ruby-json-jwt | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | ruby-json-jwt | No fix yet | — |
| Ubuntu 18.04 LTS | ruby-json-jwt | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 15 SP5 | rubygem-aes_key_wrap | 1.1.0-bp155.2.1 | openSUSE-SU-2025:0004-1 |
| SUSE Package Hub 15 SP5 | rubygem-json-jwt | 1.16.6-bp155.3.3.1 | openSUSE-SU-2025:0004-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.5 | rubygem-aes_key_wrap | 1.1.0-bp155.2.1 | openSUSE-SU-2025:0004-1 |
| openSUSE Leap 15.5 | rubygem-json-jwt | 1.16.6-bp155.3.3.1 | openSUSE-SU-2025:0004-1 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | kube-fluentd-operator +3 | 1.18.2-r3 | — |
| Wolfi rolling | ruby3.2-json-jwt | 1.16.6-r0 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| RubyGems | json-jwt | >= 1.16.0, < 1.16.6 | 1.16.6 | GHSA-c8v6-786g-vjx6 |
| RubyGems | json-jwt | < 1.15.3.1 | 1.15.3.1 | GHSA-c8v6-786g-vjx6 |
Advisories 1
- openSUSE-SU-2025:0004-1 Security update for rubygem-json-jwt SUSE / openSUSE Security Updates · Feb 4, 2026