CVE-2023-51774

json-jwt allows bypass of identity checks via a sign/encryption confusion attack

8.4 HighFix available

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.

Attack profile

How easy it is to exploit

Attack vector: Local
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

0.23%Up 0.2 points since Dec 26, 2023

What each source reports

CVE List Score used 8.4

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.

Record: CVE-2023-51774
CVSS 3.1: 8.4 HighCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-284
Updated: 2026-11-02

EUVDEUVD-2024-0613 8.4

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.

Record: EUVD-2024-0613
CVSS 3.1: 8.4 HighCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-03

GitHub AdvisoriesGHSA-c8v6-786g-vjx6 No score

json-jwt allows bypass of identity checks via a sign/encryption confusion attack

The json-jwt (aka JSON::JWT) gem 1.16.x before 1.16.6, 1.15.x before 1.15.3.1 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.

Record: GHSA-c8v6-786g-vjx6
Updated: 2026-11-02

NVD 8.4

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.

Record: CVE-2023-51774
CVSS 3.1: 8.4 HighCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-284
Updated: 2026-11-02

OSV 8.4

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.

Record: CVE-2023-51774
CVSS 3.1: 8.4 HighCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2023-51774 8.4

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.

Record: UBUNTU-CVE-2023-51774
CVSS 3.1: 8.4 HighCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVGHSA-c8v6-786g-vjx6 No score

json-jwt allows bypass of identity checks via a sign/encryption confusion attack

Record: GHSA-c8v6-786g-vjx6
Updated: 2026-11-02

OSVopenSUSE-SU-2025:0004-1 No score

Security update for rubygem-json-jwt

This update for rubygem-json-jwt fixes the following issues:

New upstream release 1.16.6, see bundled CHANGELOG.md
Remove padding oracle by @btoews in https://github.com/nov/json-jwt/pull/109
Fixes CVE-2023-51774 boo#1220727
updated to version 1.11.0
- no changelog found
- Fixes CVE-2019-18848 boo#1156649

Record: openSUSE-SU-2025:0004-1
Updated: 2026-11-02

Affected products

json-jwt project json-jwt

Affected packages

Affected packages
Package	Affected	Fixed
`json-jwt` RubyGems	1.16.0 up to 1.16.6	1.16.6
`json-jwt` RubyGems	before 1.15.3.1	1.15.3.1
`json-jwt` RubyGems	1.16.0 up to 1.16.6, plus listed versions 1.16.11.16.21.16.31.16.41.16.5	1.16.6
`json-jwt` RubyGems	before 1.15.3.1, plus listed versions 0.0.00.0.10.0.20.0.30.0.4 Show 45 moreShow less 0.0.50.0.60.0.70.1.00.1.10.1.20.1.30.1.40.1.50.1.60.1.70.1.80.2.00.3.00.3.10.3.20.3.30.4.00.4.10.4.20.4.30.5.00.5.10.5.20.5.30.5.40.5.50.5.60.6.00.6.10.7.00.7.0.alpha0.7.0.alpha20.7.10.8.00.8.11.0.01.0.11.0.21.0.31.1.01.10.01.10.11.10.21.11.0	1.15.3.1
`ruby-json-jwt` Ubuntu:18.04:LTS	All versions, plus listed versions 1.7.2-1	None known
`ruby-json-jwt` Ubuntu:20.04:LTS	All versions, plus listed versions 1.9.4-11.11.0-1	None known
`ruby-json-jwt` Ubuntu:22.04:LTS	All versions, plus listed versions 1.11.0-11.13.0-11.13.0-1ubuntu0.1	None known
`ruby-json-jwt` Ubuntu:24.04:LTS	All versions, plus listed versions 1.14.0-2	None known
`ruby-json-jwt` Ubuntu:25.10	All versions, plus listed versions 1.16.7-1	None known
`ruby-json-jwt` Ubuntu:26.10	All versions, plus listed versions 1.17.0-11.17.1-11.17.2-1	None known

Show 5 moreShow less

Affected packages
Package	Affected	Fixed
`ruby-json-jwt` Ubuntu:26.04:LTS	All versions, plus listed versions 1.16.7-11.17.0-1	None known
`rubygem-aes_key_wrap` SUSE:Package Hub 15 SP5 From an advisory covering 2 CVEs	before 1.1.0-bp155.2.1	1.1.0-bp155.2.1
`rubygem-json-jwt` SUSE:Package Hub 15 SP5 From an advisory covering 2 CVEs	before 1.16.6-bp155.3.3.1	1.16.6-bp155.3.3.1
`rubygem-aes_key_wrap` openSUSE:Leap 15.5 From an advisory covering 2 CVEs	before 1.1.0-bp155.2.1	1.1.0-bp155.2.1
`rubygem-json-jwt` openSUSE:Leap 15.5 From an advisory covering 2 CVEs	before 1.16.6-bp155.3.3.1	1.16.6-bp155.3.3.1

History

History
Recorded	Changed	Sources
Nov 6, 2026	affected, facts
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2023-51774 is a high vulnerability (CVSS 8.4) in Json-jwt Project Json-jwt, published December 25, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.23%, the 14th percentile. Fixed in json-jwt 1.16.6.

References

Show 11 moreShow less

This page doesn't list everything

Left out here: 37 versions. The JSON record has them.