dbcve.org
TomcatWeb server / proxy · Apache

CVE-2026-43515

CRITICAL · 9.1 CVSS v3.1 Published 2026-05-12
Fix available
A fix is available. Upgrade to 9.0.118 / 10.1.55 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Improper Authorization vulnerability when multiple method constraints define an HTTP method for the same extension in Apache Tomcat. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.21, from 10.1.0-M1 through 10.1.54, from 9.0.0.M1 through 9.0.117, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118 which fix the issue.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Improper authorization vulnerability in Apache Tomcat where multiple method constraints can define an HTTP method for the same extension, potentially leading to incorrect authorization decisions for web requests.

MitigationUpgrade Apache Tomcat to version 11.0.22, 10.1.55, 9.0.118, or 7.0.110 (depending on your major version) to resolve the authorization bypass in method constraint processing.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
TomcatWeb server / proxy
Affected:>= 7.0.0, <= 7.0.109>= 8.5.0, <= 8.5.100>= 9.0.0, < 9.0.118>= 10.1.0, < 10.1.55>= 11.0.0, < 11.0.22

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Apache Tomcat version
    Check the RELEASE-NOTE file in the Tomcat home directory, or run: java -cp catalina.jar org.apache.catalina.util.ServerInfo (for Tomcat 9+). On Windows, you can also check the version via the Windows Service manager if Tomcat is installed as a service.
    Affected if The installed version falls within any of these ranges: 7.0.0-7.0.109, 8.5.0-8.5.100, 9.0.0-9.0.117, 10.1.0-10.1.54, or 11.0.0-11.0.21
  2. Locate web.xml configuration files
    Check for the presence of conf/web.xml (global) and WEB-INF/web.xml (application-specific) files in your Tomcat installation and web applications. These files define security constraints.
    Affected if Security constraints are defined using <security-constraint> elements in any web.xml file
  3. Identify method constraints in web.xml
    Review all <security-constraint> definitions in web.xml files. Look for nested <http-method> or <http-method-constraint> elements. Search for any patterns where multiple constraints reference the same HTTP method (GET, POST, PUT, DELETE, etc.) for the same URL pattern.
    Affected if Multiple <security-constraint> elements define the same HTTP method (e.g., multiple constraints each specifying GET) for overlapping or identical URL patterns
  4. Check for programmatic security annotations
    Review Java source files for @ServletSecurity annotations or other JSR-250 security annotations (@RolesAllowed, @PermitAll, @DenyAll) on servlets. Also check for programmatic constraint definitions using ServletRegistration.Dynamic.addConstraint().
    Affected if Multiple method-security constraints are defined programmatically or via annotations for the same servlet or URL pattern
  5. Verify if the environment uses security constraints
    Search the Tomcat installation and deployed applications for any security configuration: grep for '<security-constraint>' in XML files, and review Java code for import org.springframework.security or javax.servlet.annotation security patterns.
    Affected if Security constraints exist and the Tomcat version is within the affected range listed above

You are affected if your Apache Tomcat version is between 7.0.0 and 7.0.109, 8.5.0 and 8.5.100, 9.0.0 and 9.0.117, 10.1.0 and 10.1.54, or 11.0.0 and 11.0.21, AND you have defined multiple HTTP method constraints (via web.xml or annotations) for the same method on overlapping URL patterns.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 9.0.118 / 10.1.55 / 11.0.22 or later
Fixed in 9.0.11810.1.5511.0.22
Interim mitigation

Upgrade Apache Tomcat to version 11.0.22, 10.1.55, 9.0.118, or 7.0.110 (depending on your major version) to resolve the authorization bypass in method constraint processing.

Recommended fix High confidence

9.0.118, 10.1.55, or 11.0.22 depending on your version branch (Tomcat 7.0.x and 8.5.x are end-of-life and require migration to a supported branch)

  1. 1. Back up the current Tomcat installation directory and all configuration files
  2. 2. Identify your current Tomcat version line (7.x, 8.5.x, 9.0.x, 10.1.x, or 11.x)
  3. 3. Download the corresponding fixed release: 9.0.118 for 9.0.x, 10.1.55 for 10.1.x, or 11.0.22 for 11.x (Tomcat 7 and 8.5 are end-of-life and users should migrate to a supported version)
  4. 4. Stop the Tomcat service or process
  5. 5. Replace the Tomcat installation files with the new version, preserving the conf directory with your custom configurations
  6. 6. Review the release notes for the new version to check for any configuration or API changes
  7. 7. Start the Tomcat service and verify the application functions correctly
  8. 8. Verify the fix is applied by checking the Tomcat version reported
Caveat Review the Tomcat release notes for the target version for any configuration changes or API deprecations; Tomcat 7.0.x and 8.5.x are end-of-life with no official fixes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Tomcat Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-43515 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data