How severe is CVE-2022-28366?

CVE-2022-28366 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2022-28366?

CVE-2022-28366 affects the following packages: net.sourceforge.htmlunit:neko-htmlunit (Maven). Ecosystems affected: Maven.

How do I fix CVE-2022-28366?

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 CVE-2022-28366 is resolved across your whole dependency graph.

How do I detect CVE-2022-28366 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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2022-28366 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-2022-28366?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2022-28366 can be triaged on real exposure rather than presence alone.

Is CVE-2022-28366 actively exploited in the wild?

No public exploit code has been indexed for CVE-2022-28366 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-2022-28366?

CVE-2022-28366 has an EPSS (Exploit Prediction Scoring System) score of 2.1%, placing it in the 81th 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 CVE-2022-28366 published, and has it been updated?

CVE-2022-28366 was published on April 21, 2022 and was last updated on August 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

HIGH severity

CVE-2022-28366 — neko-htmlunit

HIGH

CVE-2022-28366 is a high-severity (CVSS 7.5) vulnerability in net.sourceforge.htmlunit:neko-htmlunit. A fix is available for net.sourceforge.htmlunit:neko-htmlunit — see the affected versions and patch details below.

Denial of service in HtmlUnit-Neko

Also known asGHSA-g9hh-vvx3-v37v

Published

Apr 21, 2022

Updated

Aug 12, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 21, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

2.1%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs81th percentile — riskier than 81% of all scored CVEsHighest risk

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-2022-28366 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 378,156 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

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-2022-24839.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`net.sourceforge.htmlunit:neko-htmlunit`	all versions	2.27`net.sourceforge.htmlunit:neko-htmlunit: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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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 CVE-2022-28366 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-2022-28366 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2022-28366. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2022-28366 in your dependencies?

O3 Security finds CVE-2022-28366 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works