CVE-2026-23903
MEDIUMDescription
Authentication Bypass by Alternate Name vulnerability in Apache Shiro. This issue affects Apache Shiro: before 2.0.7. Users are recommended to upgrade to version 2.0.7, which fixes the issue. The issue only effects static files. If static files are served from a case-insensitive filesystem, such as default macOS setup, static files may be accessed by varying the case of the filename in the request. If only lower-case (common default) filters are present in Shiro, they may be bypassed this way. Shiro 2.0.7 and later has a new parameters to remediate this issue shiro.ini: filterChainResolver.caseInsensitive = true application.propertie: shiro.caseInsensitive=true Shiro 3.0.0 and later (upcoming) makes this the default.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Exploit Intelligence
Low risk: more likely to be exploited than 29% of all known CVEs.
References
Related Vulnerabilities
Other CWE-289 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2024-56511 | Critical | 9.8 | 44% | - | Fix |
| CVE-2021-34746 | Critical | 9.8 | 18% | - | Fix |
| CVE-2017-16590 | High | 8.8 | 3.3% | - | - |
| CVE-2026-48618 | Medium | 6.5 | 3.2% | - | Fix |
| CVE-2025-55130 | Critical | 9.1 | 1.6% | - | Fix |
| CVE-2026-44492 | High | 8.6 | 0.9% | - | Fix |
Common questions
How do I fix CVE-2026-23903?
Upgrade shiro to 2.0.7 or later.
Is CVE-2026-23903 being actively exploited?
Not that we know of. CVE-2026-23903 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.36% is the estimated probability that it will be exploited in the next 30 days. That is higher than 29% of all scored CVEs.
How severe is CVE-2026-23903?
CVE-2026-23903 has a CVSS v3 base score of 5.3, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-23903 affect?
Published advisories record a fix for shiro (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2026-23903
Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-02-11.