CVE-2026-56091Network attack vector

Unauthenticated access to protected web resources

Published Jun 25, 2026 · Updated Jun 25, 2026

Authentication bypass in Apache Shiro 2.x and earlier and 3.0.0-alpha-1 allows remote attackers to access protected web resources. Apache has not disclosed how the crafted request causes shiro-guice to omit or evade its authentication check. Exposure requires the shiro-guice module in a web servlet context; affected requests reach resources that the application intended to protect.

CVSS severity8.2
High
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Apache Shiro 2.x and earlier and 3.0.0-alpha-1 allows remote attackers to access protected web resources. Apache has not disclosed how the crafted request causes shiro-guice to omit or evade its authentication check. Exposure requires the shiro-guice module in a web servlet context; affected requests reach resources that the application intended to protect.

The record

CVE
CVE-2026-56091
Published
Jun 25, 2026
Updated
Jun 25, 2026
Vendor
The Apache Software Foundation
Product
Apache Shiro
Classifications
CWE-289, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=2.99.99
  2. Affected versionversion=3.0.0-alpha-0 <=3.0.0-alpha-1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache Shiroversion=0 <=2.99.99; version=3.0.0-alpha-0 <=3.0.0-alpha-1

Published CVSS scores

8.2Apache Software FoundationCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-289Authentication Bypass by Alternate Name
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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