CVE-2026-24733 — tomcat-coyote
MEDIUMCVE-2026-24733 is a medium-severity (CVSS 6.5) Improper Input Validation vulnerability in org.apache.tomcat:tomcat-coyote. A fix is available for org.apache.tomcat:tomcat-coyote — see the affected versions and patch details below.
Apache Tomcat: Security constraint bypass with HTTP/0.9
Exploitation Status
No confirmed exploitation observed yet
- 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-2026-24733.
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-2026-24733 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 377,238 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-coyote☕org.apache.tomcat:tomcat-coyote☕org.apache.tomcat:tomcat-coyoteReal-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 Input Validation vulnerability in Apache Tomcat.
Tomcat did not limit HTTP/0.9 requests to the GET method. If a security constraint was configured to allow HEAD requests to a URI but deny GET requests, the user could bypass that constraint on GET requests by sending a (specification invalid) HEAD request using HTTP/0.9.
This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.14, from 10.1.0-M1 through 10.1.49, from 9.0.0.M1 through 9.0.112.
Older, EOL versions are also affected.
Users are recommended to upgrade to version 11.0.15 or later, 10.1.50 or later or 9.0.113 or later, which fixes the issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.tomcat:tomcat-coyote | ≥ 11.0.0-M1&&< 11.0.15 | 11.0.15org.apache.tomcat:tomcat-coyote:11.0.15 |
| ☕Maven | org.apache.tomcat:tomcat-coyote | ≥ 10.1.0-M1&&< 10.1.50 | 10.1.50org.apache.tomcat:tomcat-coyote:10.1.50 |
| ☕Maven | org.apache.tomcat:tomcat-coyote | all versions | 9.0.113org.apache.tomcat:tomcat-coyote:9.0.113 |
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-coyote, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.tomcat:tomcat-coyote to 11.0.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-24733 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-2026-24733 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-24733. 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 flaw is only exploitable when Tomcat is configured to allow HEAD requests but deny GET requests to the same resource, a very unlikely configuration. Due to this reason, this flaw has been rated with a low severity.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 10 | tomcat9-1:9.0.117-2.el10_2 | RHSA-2026:36790 |
| Red Hat JBoss Web Server 6.2.2 | see advisory | RHSA-2026:12195 |
| Red Hat JBoss Web Server 6.2 on RHEL 10 | jws6-tomcat-0:10.1.49-10.redhat_00008.1.el10jws | RHSA-2026:12194 |
| Red Hat Hardened Images | tomcat11-main-11.0.21-0.1.hum1 | RHSA-2026:6569 |
| Red Hat Hardened Images | tomcat10-main-10.1.54-1.hum1 | RHSA-2026:8334 |
Frequently Asked Questions
Is CVE-2026-24733 in your dependencies?
O3 Security finds CVE-2026-24733 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.