CVE-2026-56091
CVE-2026-56091 is a high-severity vulnerability with a CVSS 4.0 base score of 8.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-289.
Key facts
- Severity: High (CVSS 4.0 base score 8.2)
- EPSS exploit prediction: 0% (34th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-39230
- Weakness: CWE-289
- Published:
- Last modified:
Description
When using Apache Shiro with the shiro-guice module in a web servlet context, a specially crafted HTTP request may cause an authentication bypass. This vulnerability is similar to https://www.cve.org/CVERecord?id=CVE-2020-1957 https://www.cve.org/CVERecord , except that it affects the `shiro-guice` module instead of the `shiro-spring` module. This issue affects all Apache Shiro versions through 2.x, and 3.0.0-alpha-1 only when using `shiro-guice` module in a web servlet context. Upgrade to version 3.0.0 or later, which fixes the issue.
Frequently asked questions
- What is CVE-2026-56091?
- When using Apache Shiro with the shiro-guice module in a web servlet context, a specially crafted HTTP request may cause an authentication bypass. This vulnerability is similar to https://www.cve.org/CVERecord?id=CVE-2020-1957 https://www.cve.org/CVERecord , except that it affects the `shiro-guice` module instead of the `shiro-spring` module. This issue affects all Apache Shiro versions through 2.x, and 3.0.0-alpha-1 only when using `shiro-guice` module in a web servlet context. Upgrade to version 3.0.0 or later, which fixes the issue.
- How severe is CVE-2026-56091?
- CVE-2026-56091 has a CVSS 4.0 base score of 8.2, rated high severity.
- Is CVE-2026-56091 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-56091?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-56091 have an EU (EUVD) identifier?
- Yes. CVE-2026-56091 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39230.
- When was CVE-2026-56091 published?
- CVE-2026-56091 was published on 2026-06-25.
References
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