PatchTheCVECVE-2016-5431: The PHP JOSE Library by Gree Inc
CVE-2016-5431 is a high-severity flaw (CVSS 7.5) affecting php jose. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
The PHP JOSE Library by Gree Inc. before version 2.2.1 is vulnerable to key confusion/algorithm substitution in the JWS component resulting in bypassing the signature verification via crafted tokens.
Why this priority
- High severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 7.5 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 1.0% (top 39%) |
| CISA exploited list | No |
| Weakness | CWE-327 |
| Published | 2019-08-07 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2016-5431?
php jose: upgrade to 2.2.1. Exact commands for each OS are on this page.
Is CVE-2016-5431 being exploited?
CVE-2016-5431 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2016-5431 affect?
CVE-2016-5431 affects php jose. Severity is high (CVSS 7.5). The PHP JOSE Library by Gree Inc. before version 2.2.1 is vulnerable to key confusion/algorithm substitution in the JWS component resulting in bypassing the signature verification via crafted tokens.
How urgent is CVE-2016-5431?
Priority 47/100. High severity; Remotely exploitable, no login, no user action