CVE-2016-4437Actively exploitedAdded to KEV 2021-11-03

Apache Shiro Code Execution Vulnerability

Apache, Shiro

Description

Apache Shiro contains a vulnerability which may allow remote attackers to execute code or bypass intended access restrictions via an unspecified request parameter when a cipher key has not been configured for the "remember me" feature.

CVSS severity for this advisory hasn't been enriched from NVD yet, check back shortly.

EPSS, exploit probability

Critical

93.0%

estimated chance of real-world exploitation in the next 30 days, higher than 99.8% of every CVE FIRST.org scores

Refreshed 10/28/2026, via FIRST.org's EPSS model, not CVSS, this measures likelihood of exploitation, not how severe it would be.

Required action

Apply updates per vendor instructions.

CISA-recommended due date: 2022-05-03

CWE-284

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