How severe is CVE-2023-28709?

CVE-2023-28709 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-28709?

CVE-2023-28709 affects the following packages: org.apache.tomcat.embed:tomcat-embed-core (Maven), org.apache.tomcat.embed:tomcat-embed-core (Maven), org.apache.tomcat.embed:tomcat-embed-core (Maven), org.apache.tomcat:tomcat-coyote (Maven). Ecosystems affected: Maven.

How do I fix CVE-2023-28709?

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.

How do I detect CVE-2023-28709 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat.embed:tomcat-embed-core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2023-28709 if there is no patch (or I can't update yet)?

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 does O3 Security protect against CVE-2023-28709?

O3 pinpoints whether CVE-2023-28709 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2023-28709 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-28709 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-28709?

CVE-2023-28709 has an EPSS (Exploit Prediction Scoring System) score of 51.5%, placing it in the 99th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

When was CVE-2023-28709 published, and has it been updated?

CVE-2023-28709 was published on May 22, 2023 and was last updated on April 16, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2023-28709: Apache Tomcat - Fix for CVE-2023-24998 was inco…

EPSS Exploitation Probability

via FIRST.org ↗

51.5%probability of exploitation in next 30 days

High Risk99th percentile+51.03%

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.

Blast Radius

4 pkgs affected

☕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-coyote

Real-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

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.tomcat.embed:tomcat-embed-core`	≥ 11.0.0-M2&&< 11.0.0-M5	11.0.0-M5
☕Maven	`org.apache.tomcat.embed:tomcat-embed-core`	≥ 10.1.5&&< 10.1.8	10.1.8
☕Maven	`org.apache.tomcat.embed:tomcat-embed-core`	≥ 9.0.71&&< 9.0.74	9.0.74
☕Maven	`org.apache.tomcat:tomcat-coyote`	≥ 8.5.85&&< 8.5.88	8.5.88

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat.embed:tomcat-embed-core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
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 pinpoints whether CVE-2023-28709 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

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.

Frequently Asked Questions

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.

O3 Security · Impact-Aware SCA

Is CVE-2023-28709 in your dependencies?

O3 detects CVE-2023-28709 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works

CVE-2023-28709