How severe is GHSA-4j3c-42xv-3f84?

GHSA-4j3c-42xv-3f84 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-4j3c-42xv-3f84?

GHSA-4j3c-42xv-3f84 affects the following packages: org.apache.tomcat:tomcat-util (Maven), org.apache.tomcat:tomcat-util (Maven). Ecosystems affected: Maven.

How do I fix GHSA-4j3c-42xv-3f84?

Update org.apache.tomcat:tomcat-util to 9.0.107 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4j3c-42xv-3f84 is resolved across your whole dependency graph.

How do I detect GHSA-4j3c-42xv-3f84 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat:tomcat-util. 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 GHSA-4j3c-42xv-3f84 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 GHSA-4j3c-42xv-3f84?

O3 pinpoints whether GHSA-4j3c-42xv-3f84 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 GHSA-4j3c-42xv-3f84 actively exploited in the wild?

No public exploit code has been indexed for GHSA-4j3c-42xv-3f84 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 GHSA-4j3c-42xv-3f84?

GHSA-4j3c-42xv-3f84 has an EPSS (Exploit Prediction Scoring System) score of 1.8%, placing it in the 76th 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. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-4j3c-42xv-3f84?

GHSA-4j3c-42xv-3f84 is classified as CWE-362 (CWE-362). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-4j3c-42xv-3f84 published, and has it been updated?

GHSA-4j3c-42xv-3f84 was published on July 10, 2025 and was last updated on May 18, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

GHSA-4j3c-42xv-3f84: tomcat-util (High 7.5)

EPSS Exploitation Probability

via FIRST.org ↗

1.8%probability of exploitation in next 30 days

Lower Risk76th percentile+0.61%

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

2 pkgs affected

☕org.apache.tomcat:tomcat-util☕org.apache.tomcat:tomcat-util

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

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in Apache Tomcat when using the APR/Native connector. This was particularly noticeable with client initiated closes of HTTP/2 connections.

This issue affects Apache Tomcat: from 9.0.0.M1 through 9.0.106. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 through 8.5.100. Other, older, EOL versions may also be affected.

Users are recommended to upgrade to version 9.0.107, which fixes the issue.

Affected Packages

2 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.tomcat:tomcat-util`	≥ 9.0.0.M1&&< 9.0.107	9.0.107
☕Maven	`org.apache.tomcat:tomcat-util`	≥ 8.5.0	No fix

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:tomcat-util. 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:tomcat-util to 9.0.107 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4j3c-42xv-3f84 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 GHSA-4j3c-42xv-3f84 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 GHSA-4j3c-42xv-3f84. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in Apache Tomcat when using the APR/Native connector. This was particularly noticeable with client initiated closes of HTTP/2 connections. This issue affects Apache Tomcat: from 9.0.0.M1 through 9.0.106. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 through 8.5.100. Other, older, EOL versions may also be affected. Users are recommended to upgrade to version 9.0.107, which fixes the issue.

O3 Security · Impact-Aware SCA

Is GHSA-4j3c-42xv-3f84 in your dependencies?

O3 detects GHSA-4j3c-42xv-3f84 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

GHSA-4j3c-42xv-3f84