CVE-2018-1000539 json
Json-jwt did not verify the cryptographic signature for data
published 2018-06-26 8 y ago modified 2026-06-17 4 mo ago also GHSA-mj4x-wcxf-hm8x , EUVD-2018-0296
- cvss
- 5.3
- version 3.0, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.8%
- EPSS 0.8% chance of exploitation in 30 days, percentile 55%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- rubygems json-jwt 1.9.4
- json-jwt_project json-jwt 1.9.4
- ruby-json-jwt Debian 14, Debian 13, Debian 12 1.9.4-1
debian advisories DEBIAN-CVE-2018-1000539
- github.com/nov/json-jwt@a3b2147 commit
- github.com/nov/json-jwt#62 pull request
Exploit prediction
0.77% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.0 | 5.3 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:P/A:N |
| GitHub | 3.0 | 5.3 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| rubygems | json-jwt | >=0.5.1, <1.9.4 |
1.9.4 |
Classification
- Weakness
-
- CWE-347 Improper Verification of Cryptographic Signature
References
-
github.com
/nov/json-jwt/pull/62
web, third-party-advisory
-
github.com
/nov/json-jwt/commit/a3b2147f0f6d9aca653e7a30e453d3a92b33413f
web
-
debian.org
/security/2018/dsa-4283
vendor-advisory, web
-
nvd.nist.gov
/vuln/detail/CVE-2018-1000539
advisory
-
github.com
/nov/json-jwt
package
-
github.com
/rubysec/ruby-advisory-db/blob/master/gems/json-jwt/CVE-2018-1000539.yml
web
Sources
- CVE List CVE-2018-1000539
- GitHub Advisory GHSA-mj4x-wcxf-hm8x
- NVD CVE-2018-1000539
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