PatchTheCVECVE-2016-10555: Since "algorithm" isn't enforced in jwt.decode()in jwt-simple 0.3.0 and earlier, a malicious user could choose
CVE-2016-10555 is a medium-severity flaw (CVSS 6.5) affecting jwt-simple. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Since "algorithm" isn't enforced in jwt.decode()in jwt-simple 0.3.0 and earlier, a malicious user could choose what algorithm is sent sent to the server. If the server is expecting RSA but is sent HMAC-SHA with RSA's public key, the server will think the public key is actually an HMAC private key. This could be used to forge any data an attacker wants.
Why this priority
- EPSS top 8%: very likely to be exploited
A fixed release or distro patch exists.
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-2016-10555?
jwt-simple: upgrade to newer than 0.3.0. Exact commands for each OS are on this page.
Is CVE-2016-10555 being exploited?
CVE-2016-10555 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-2016-10555 affect?
CVE-2016-10555 affects jwt-simple. Severity is medium (CVSS 6.5). Since "algorithm" isn't enforced in jwt.decode()in jwt-simple 0.3.0 and earlier, a malicious user could choose what algorithm is sent sent to the server. If the server is expecting RSA but is sent HMAC-SHA with RSA's public key, the server
How urgent is CVE-2016-10555?
Priority 46/100. EPSS top 8%: very likely to be exploited