CVE-2023-28709 — tomcat-embed-core
HIGHCVE-2023-28709 is a high-severity (CVSS 7.5) CWE-193 vulnerability in org.apache.tomcat.embed:tomcat-embed-core. EPSS puts its 30-day exploitation probability at 48.0% (99th percentile). A fix is available for org.apache.tomcat.embed:tomcat-embed-core — see the affected versions and patch details below.
Apache Tomcat: Fix for CVE-2023-24998 is incomplete
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.
- 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-2023-28709.
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-2023-28709 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 377,166 CVEs with a current EPSS score, this one falls in the 10–50% 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.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core☕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
The fix for CVE-2023-24998 was incomplete for Apache Tomcat 11.0.0-M2 to 11.0.0-M4, 10.1.5 to 10.1.7, 9.0.71 to 9.0.73 and 8.5.85 to 8.5.87. If non-default HTTP connector settings were used such that the maxParameterCount could be reached using query string parameters and a request was submitted that supplied exactly maxParameterCount parameters in the query string, the limit for uploaded request parts could be bypassed with the potential for a denial of service to occur.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.tomcat.embed:tomcat-embed-core | ≥ 11.0.0-M2&&< 11.0.0-M5 | 11.0.0-M5org.apache.tomcat.embed:tomcat-embed-core:11.0.0-M5 |
| ☕Maven | org.apache.tomcat.embed:tomcat-embed-core | ≥ 10.1.5&&< 10.1.8 | 10.1.8org.apache.tomcat.embed:tomcat-embed-core:10.1.8 |
| ☕Maven | org.apache.tomcat.embed:tomcat-embed-core | ≥ 9.0.71&&< 9.0.74 | 9.0.74org.apache.tomcat.embed:tomcat-embed-core:9.0.74 |
| ☕Maven | org.apache.tomcat:tomcat-coyote | ≥ 8.5.85&&< 8.5.88 | 8.5.88org.apache.tomcat:tomcat-coyote:8.5.88 |
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.embed:tomcat-embed-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.tomcat.embed:tomcat-embed-core to 11.0.0-M5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-28709 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-2023-28709 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-28709. 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.
The impact for this flaw is considered moderate to match the Apache Software Foundation impact, considering the non-default configuration in CVE description. pki-servlet-engine has been obsoleted in Red Hat Enterprise Linux 8.9 and later by Tomcat, so no additional fixes for the engine would be made available.
| Product | Fixed in | Advisory |
|---|---|---|
| JWS 5.7.4 release | tomcat | RHSA-2023:4910 |
| Red Hat Enterprise Linux 8 | tomcat-1:9.0.62-27.el8_9 | RHSA-2023:7065 |
| Red Hat Enterprise Linux 9 | tomcat-1:9.0.62-37.el9_3 | RHSA-2023:6570 |
| Red Hat JBoss Web Server 5.7 on RHEL 7 | jws5-tomcat-0:9.0.62-15.redhat_00013.1.el7jws | RHSA-2023:4909 |
Frequently Asked Questions
Is CVE-2023-28709 in your dependencies?
O3 Security finds CVE-2023-28709 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.