How severe is GHSA-g9hh-vvx3-v37v?

GHSA-g9hh-vvx3-v37v has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-g9hh-vvx3-v37v?

GHSA-g9hh-vvx3-v37v affects the following packages: net.sourceforge.htmlunit:neko-htmlunit (Maven). Ecosystems affected: Maven.

How do I fix GHSA-g9hh-vvx3-v37v?

Update net.sourceforge.htmlunit:neko-htmlunit to 2.27 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-g9hh-vvx3-v37v is resolved across your whole dependency graph.

How do I detect GHSA-g9hh-vvx3-v37v in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for net.sourceforge.htmlunit:neko-htmlunit. 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-g9hh-vvx3-v37v 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-g9hh-vvx3-v37v?

O3 pinpoints whether GHSA-g9hh-vvx3-v37v 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-g9hh-vvx3-v37v actively exploited in the wild?

No public exploit code has been indexed for GHSA-g9hh-vvx3-v37v 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-g9hh-vvx3-v37v?

GHSA-g9hh-vvx3-v37v has an EPSS (Exploit Prediction Scoring System) score of 2.0%, placing it in the 78th 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.

When was GHSA-g9hh-vvx3-v37v published, and has it been updated?

GHSA-g9hh-vvx3-v37v was published on April 23, 2022 and was last updated on December 5, 2024. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

GHSA-g9hh-vvx3-v37v: Denial of service in HtmlUnit-Neko (High 7…

EPSS Exploitation Probability

via FIRST.org ↗

2.0%probability of exploitation in next 30 days

Lower Risk78th percentile+1.78%

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

1 pkg affected

☕net.sourceforge.htmlunit:neko-htmlunit

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

Certain Neko-related HTML parsers allow a denial of service via crafted Processing Instruction (PI) input that causes excessive heap memory consumption. In particular, this issue exists in HtmlUnit-Neko through 2.26, and is fixed in 2.27. This issue also exists in CyberNeko HTML through 1.9.22 (also affecting OWASP AntiSamy before 1.6.6), but 1.9.22 is the last version of CyberNeko HTML. NOTE: this may be related to CVE-2022-24939.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`net.sourceforge.htmlunit:neko-htmlunit`	all versions	2.27

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for net.sourceforge.htmlunit:neko-htmlunit. 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 net.sourceforge.htmlunit:neko-htmlunit to 2.27 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-g9hh-vvx3-v37v 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-g9hh-vvx3-v37v 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-g9hh-vvx3-v37v. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Certain Neko-related HTML parsers allow a denial of service via crafted Processing Instruction (PI) input that causes excessive heap memory consumption. In particular, this issue exists in HtmlUnit-Neko through 2.26, and is fixed in 2.27. This issue also exists in CyberNeko HTML through 1.9.22 (also affecting OWASP AntiSamy before 1.6.6), but 1.9.22 is the last version of CyberNeko HTML. NOTE: this may be related to CVE-2022-24939.

O3 Security · Impact-Aware SCA

Is GHSA-g9hh-vvx3-v37v in your dependencies?

O3 detects GHSA-g9hh-vvx3-v37v 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-g9hh-vvx3-v37v