CVE-2025-31651 is a critical-severity (CVSS 9.8) CWE-116 vulnerability in org.apache.tomcat:tomcat-catalina. A fix is available for org.apache.tomcat:tomcat-catalina — see the affected versions and patch details below.
Apache Tomcat: Bypass of rules in Rewrite Valve
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-31651.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2025-31651 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
org.apache.tomcat:tomcat-catalina☕org.apache.tomcat:tomcat-catalina☕org.apache.tomcat:tomcat-catalina☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat:tomcat-catalina☕org.apache.tomcat.embed:tomcat-embed-coreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
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 9.0.104, 10.1.40 or 11.0.6, which fix the issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.tomcat:tomcat-catalina | ≥ 9.0.76&&< 9.0.104 | 9.0.104org.apache.tomcat:tomcat-catalina:9.0.104 |
| ☕Maven | org.apache.tomcat:tomcat-catalina | ≥ 10.1.10&&< 10.1.40 | 10.1.40org.apache.tomcat:tomcat-catalina:10.1.40 |
| ☕Maven | org.apache.tomcat:tomcat-catalina | ≥ 11.0.0-M2&&< 11.0.6 | 11.0.6org.apache.tomcat:tomcat-catalina:11.0.6 |
| ☕Maven | org.apache.tomcat.embed:tomcat-embed-core | ≥ 9.0.76&&< 9.0.104 | 9.0.104org.apache.tomcat.embed:tomcat-embed-core:9.0.104 |
| ☕Maven | org.apache.tomcat.embed:tomcat-embed-core | ≥ 10.1.10&&< 10.1.40 | 10.1.40org.apache.tomcat.embed:tomcat-embed-core:10.1.40 |
| ☕Maven | org.apache.tomcat.embed:tomcat-embed-core | ≥ 11.0.0-M2&&< 11.0.6 | 11.0.6org.apache.tomcat.embed:tomcat-embed-core:11.0.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat:tomcat-catalina, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.tomcat:tomcat-catalina to 9.0.104 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-31651 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-31651 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-31651. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This vulnerability is rated as Low severity because it only manifests under a narrow set of conditions involving uncommon and non-default rewrite rule configurations that rely on specific patterns in the raw requestURI, including path parameters. In most deployments, rewrite rules operate on decoded and normalized…
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 10 | tomcat-1:10.1.36-3.el10_1.1 | RHSA-2025:23050 |
| Red Hat Enterprise Linux 10 | tomcat9-1:9.0.87-8.el10_1.1 | RHSA-2025:23052 |
| Red Hat Enterprise Linux 10.0 Extended Update Support | tomcat-1:10.1.36-1.el10_0.3 | RHSA-2025:23051 |
| Red Hat Enterprise Linux 10.0 Extended Update Support | tomcat9-1:9.0.87-5.el10_0.4 | RHSA-2025:23053 |
| Red Hat Enterprise Linux 8 | tomcat-1:9.0.87-1.el8_10.7 | RHSA-2025:23048 |
| Red Hat Enterprise Linux 8.2 Advanced Update Support | pki-deps:10.6-8020020260128173505.4cda2c84 | RHSA-2026:2725 |
| Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | pki-deps:10.6-8040020260129154709.522a0ee4 | RHSA-2026:2724 |
| Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | pki-deps:10.6-8060020260128101437.ad008a3a | RHSA-2026:2726 |
Frequently Asked Questions
Is CVE-2025-31651 in your dependencies?
O3 Security finds CVE-2025-31651 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.