CVE Almanac
← All CVEs

CVE-2026-56091

HIGH 8.2

Published 2026-06-25 · Last modified 2026-06-25

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.

ELEVATED IMPACT

Severe if exploited (CVSS 8.2), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.4%chance of exploitation in 30 days · 34th percentile

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

8.2CVSS 4.0 · HIGH

  • ConfidentialityHigh
  • IntegrityNone
  • AvailabilityNone

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ✓Privileges: No account or privileges required
  • ✓User interaction: No user interaction needed
  • ✓Complexity: No special conditions — reliably repeatable
  • ⚠Requirements: Specific conditions must be present

✓ lowers the bar for an attacker · ⚠ raises it

Affected

Vendors Apache Software Foundation

Products Apache Shiro

Weakness (CWE)

  • CWE-289

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/S:P/AU:Y/V:D/RE:L/U:Amber

References

Advisories

Sources: NVD · CVE.org · EPSS