CVE-2026-23903Network attack vector

Unauthenticated static-file access via case-variant paths

Published Feb 9, 2026 · Updated Feb 9, 2026

Authentication bypass in Apache Shiro before 2.0.7 allows remote attackers to read protected static files through case-variant requests. PathMatchingFilterChainResolver compares request paths case-sensitively while a case-insensitive filesystem resolves differently cased names to the same file. Exposure requires protected static files on a case-insensitive filesystem with lower-case-only filter rules; dynamic resources are unaffected.

CVSS severity5.3
Medium
EPSS probability0.36%
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 before 2.0.7 allows remote attackers to read protected static files through case-variant requests. PathMatchingFilterChainResolver compares request paths case-sensitively while a case-insensitive filesystem resolves differently cased names to the same file. Exposure requires protected static files on a case-insensitive filesystem with lower-case-only filter rules; dynamic resources are unaffected.

The record

CVE
CVE-2026-23903
Published
Feb 9, 2026
Updated
Feb 9, 2026
Vendor
The Apache Software Foundation
Product
Apache Shiro
Classifications
CWE-289, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 9, 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 <2.0.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache Shiroversion=0 <2.0.7

Published CVSS scores

5.3GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A: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.

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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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