dbcve.org
TomcatWeb server / proxy · Apache

CVE-2025-31651

CRITICAL · 9.8 CVSS v3.1 Published 2025-04-28
Fix available
A fix is available. Upgrade to 9.0.104 / 10.1.40 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 Neutralization of Escape, Meta, or Control Sequences vulnerability in Apache Tomcat. For a subset of unlikely rewrite rule configurations, it was possible for a specially crafted request to bypass some rewrite rules. If those rewrite rules effectively enforced security constraints, those constraints could be bypassed. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.5, from 10.1.0-M1 through 10.1.39, from 9.0.0.M1 through 9.0.102. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 though 8.5.100. Other, older, EOL versions may also be affected. Users are recommended to upgrade to version [FIXED_VERSION], which fixes 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 · high confidence

Improper neutralization vulnerability in Apache Tomcat's rewrite module allows specially crafted requests with escape, meta, or control sequences to bypass rewrite rules. When those rules enforce security constraints, those constraints can be circumvented. This affects specific (unlikely) rewrite rule configurations.

MitigationUpgrade to the fixed version of Apache Tomcat as specified in the security advisory, or if using affected rewrite rule configurations, review and harden those rules as an interim measure.

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:>= 9.0.0, < 9.0.104>= 10.1.0, < 10.1.40>= 11.0.0, < 11.0.6

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
High

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

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 Apache Tomcat installation and version
    Locate the Tomcat installation directory (typically CATALINA_HOME) and check the version by examining the RELEASE-NOTE file in the CATALINA_HOME directory, or run 'java -cp catalina.jar org.apache.catalina.util.ServerInfo' to retrieve the server version programmatically.
    Affected if The installed version falls within 9.0.0 to 9.0.103, 10.1.0 to 10.1.39, or 11.0.0 to 11.0.5.
  2. Verify the rewrite valve is enabled
    Inspect the server.xml file in the CATALINA_HOME/conf directory for a RewriteValve element inside the Host configuration, or check the context.xml file (either in CATALINA_HOME/conf or within the application's WEB-INF directory) for a RewriteValve nested inside the Context element. The valve is configured as a Valve with className org.apache.catalina.valves.rewrite.RewriteValve.
    Affected if The rewrite valve is present and enabled in either server.xml or context.xml.
  3. Locate rewrite rule configuration
    Check for the presence of a rewrite.config file in the application's WEB-INF directory, or in the conf/Catalina/localhost/ directory under the webapp's context path. These files contain the rewrite rules defined for the application.
    Affected if A rewrite.config file exists and contains rewrite rules.
  4. Identify security-enforcing rewrite rules
    Examine the rewrite.config file for rules that enforce security constraints such as IP restrictions (using rewritecond with remote host conditions), authentication requirements, authorization checks, or URL access controls that are intended to block unauthorized access to sensitive resources.
    Affected if The rewrite rules include conditions or rules that enforce security constraints (such as blocking access based on IP, user agent, or requiring specific URL patterns for protected resources).

A user is affected if they are running a vulnerable Tomcat version (9.0.0-9.0.103, 10.1.0-10.1.39, or 11.0.0-11.0.5) AND the rewrite valve is enabled AND rewrite rules with security constraints are configured.

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 9.0.104 / 10.1.40 / 11.0.6 or later
Fixed in 9.0.10410.1.4011.0.6
Interim mitigation

Upgrade to the fixed version of Apache Tomcat as specified in the security advisory, or if using affected rewrite rule configurations, review and harden those rules as an interim measure.

Recommended fix High confidence

Tomcat 9.0.104 (or 10.1.40 for 10.1.x, or 11.0.6 for 11.x)

  1. 1. Identify the currently installed Apache Tomcat version by checking the $CATALINA_HOME/RELEASE-NOTES file or running 'version.sh' (or 'version.bat' on Windows)
  2. 2. Based on your major version (9.x, 10.1.x, or 11.x), determine the minimum fixed version needed
  3. 3. Download the corresponding Apache Tomcat release from the official Apache Tomcat downloads page (https://tomcat.apache.org/download-90.cgi, https://tomcat.apache.org/download-101.cgi, or https://tomcat.apache.org/download-110.cgi)
  4. 4. Stop the Tomcat service/instance
  5. 5. Back up your existing Tomcat installation directory, including all configuration files in conf/ and web applications in webapps/
  6. 6. Extract the new Tomcat version to your installation directory
  7. 7. Restore your custom configuration files from the backup (server.xml, context.xml, etc.)
  8. 8. Restore any custom web applications from the backup
Caveat Minimal risk - this is a patch release with security fixes; review release notes for any minor behavioral changes in the rewrite valve

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
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.

Scan for this in your stack

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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-2025-31651 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