OutOfMemory Exception by specifically crafted processing instruction in NekoHtml Parser

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2022-29546: 1.23% estimated exploitation activity in the next 30 days; percentile 69.00 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact NekoHtml Parser suffers from a denial of service vulnerability on versions 2.60.0 and below. A specifically crafted input regarding the parsing of processing instructions leads to heap memory consumption. Please update to version 2.61.0. For more information If you have any questions or comments about this advisory: Open an issue in https://github.com/HtmlUnit/htmlunit-neko Email us at [rbri at rbri.de]

Published by the source

26 Apr 2022, 21:14 UTC

Last modified by the source

27 Jan 2023, 05:02 UTC

Source last checked

26 Oct 2026, 15:59 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-6jmm-mp6w-4rrg

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# Patch Next advisory brief: CVE-2022-29546

Advisory: OutOfMemory Exception by specifically crafted processing instruction in NekoHtml Parser
IDs: CVE-2022-29546, GHSA-6jmm-mp6w-4rrg
Record: https://patchnext.com/advisories/cve-2022-29546 (revision 1, source checked 26 Oct 2026, 15:59 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: net.sourceforge.htmlunit:neko-htmlunit 2.61.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven net.sourceforge.htmlunit:neko-htmlunit: affected < 2.61.0; fixed in 2.61.0

## Suggested inspection (read-only)
- Maven net.sourceforge.htmlunit:neko-htmlunit: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on net.sourceforge.htmlunit:neko-htmlunit.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-6jmm-mp6w-4rrg (GitHub-reviewed advisory GHSA-6jmm-mp6w-4rrg lists affected ranges: Maven net.sourceforge.htmlunit:neko-htmlunit >=0 <2.61.0)

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