Apache Shiro shiro-guice module vulnerable to authentication bypass

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.2 · 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 · score source

EPSS

• CVE-2026-56091: 0.67% estimated exploitation activity in the next 30 days; percentile 52.01 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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, 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.

Published by the source

25 Jun 2026, 09:31 UTC

Last modified by the source

3 Nov 2026, 21:31 UTC

Source last checked

4 Nov 2026, 06:30 UTC

1. Revision 2 · amended · 4 Nov 2026

   Amended from osv record GHSA-qj64-jj84-w38j

2. Revision 1 · created · 3 Nov 2026

   Published from ghsa record GHSA-qj64-jj84-w38j

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-56091

Advisory: Apache Shiro shiro-guice module vulnerable to authentication bypass
IDs: CVE-2026-56091, GHSA-qj64-jj84-w38j
Record: https://patchnext.com/advisories/cve-2026-56091 (revision 2, source checked 4 Nov 2026, 06:30 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.apache.shiro:shiro-guice 3.0.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.apache.shiro:shiro-guice: affected >= 2.0.0, < 3.0.0; fixed in 3.0.0

## Suggested inspection (read-only)
- Maven org.apache.shiro:shiro-guice: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.apache.shiro:shiro-guice.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-qj64-jj84-w38j (GitHub-reviewed advisory GHSA-qj64-jj84-w38j lists affected ranges: Maven org.apache.shiro:shiro-guice >=2.0.0 <3.0.0)
- Verified: https://osv.dev/vulnerability/GHSA-qj64-jj84-w38j (OSV record GHSA-qj64-jj84-w38j lists affected ranges: Maven org.apache.shiro:shiro-guice >=2.0.0 <3.0.0 (fixed))

Commands are suggestions: review each one before running it.