mXSS in AntiSamy

Exploitation

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

CVSS

6.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS

• CVE-2023-43643: 0.54% estimated exploitation activity in the next 30 days; percentile 45.53 (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 There is a potential for a mutation XSS (mXSS) vulnerability in AntiSamy caused by flawed parsing of the HTML being sanitized. To be subject to this vulnerability the preserveComments directive must be enabled in your policy file and also allow for certain tags at the same time. As a result, certain crafty inputs can result in elements in comment tags being interpreted as executable when using AntiSamy's sanitized output. Patches Patched in AntiSamy 1.7.4 and later. See important remediation details in the reference given below. Workarounds If you cannot upgrade to a fixed version of the library, the following mitigation can be applied until you can upgrade: Manually edit your AntiSamy policy file (e.g., antisamy.xml) by deleting the preserveComments directive or setting its value to false, if present. Also it would be useful to make AntiSamy remove the noscript tag by adding this in your tag definitions under the <tagrules node (or deleting it entirely if present): As the…

Published by the source

9 Oct 2023, 00:42 UTC

Last modified by the source

5 Nov 2023, 05:05 UTC

Source last checked

26 Oct 2026, 16:16 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-pcf2-gh6g-h5r2

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# Patch Next advisory brief: CVE-2023-43643

Advisory: mXSS in AntiSamy
IDs: CVE-2023-43643, GHSA-pcf2-gh6g-h5r2
Record: https://patchnext.com/advisories/cve-2023-43643 (revision 1, source checked 26 Oct 2026, 16:16 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.owasp.antisamy:antisamy 1.7.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.owasp.antisamy:antisamy: affected <= 1.7.3; fixed in 1.7.4

## Suggested inspection (read-only)
- Maven org.owasp.antisamy:antisamy: 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 org.owasp.antisamy:antisamy.
- 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-pcf2-gh6g-h5r2 (GitHub-reviewed advisory GHSA-pcf2-gh6g-h5r2 lists affected ranges: Maven org.owasp.antisamy:antisamy >=0 <=1.7.3)

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