Graby has stored XSS via iframe srcdoc Attribute in htmLawed Sanitization Config

Exploitation

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

CVSS 4.0

2.1 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:P · score source

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary Graby's cleanupXss() function configures htmLawed with conflicting settings: safe=1 (which removes <iframe) combined with 'elements' = '+iframe-meta' (which re-enables <iframe). htmLawed does not sanitize the srcdoc attribute, allowing injection of arbitrary JavaScript that executes when the content is rendered via |raw in templates. Root Cause src/Graby.php lines 1038-1048: The safe=1 and +iframe combination is a conflict: safe mode is designed to strip dangerous elements, but the elements override re-enables <iframe without also blocking the dangerous srcdoc attribute. Proof of Concept Input to cleanupXss(): Output (unchanged — htmLawed passes it through): When rendered via {{ content|raw }} in a template, srcdoc executes in an about:srcdoc frame with the same origin as the page. Confirmed via Puppeteer/Chromium headless: alert(document.domain) fires. Validated on Wallabag (which uses Graby) via Docker: entry created via API with iframe-only content body triggers…

Published by the source

31 Mar 2026, 23:12 UTC

Last modified by the source

31 Mar 2026, 23:12 UTC

Source last checked

26 Oct 2026, 14:39 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-3h6j-9x8m-rg3g

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# Patch Next advisory brief: GHSA-3h6j-9x8m-rg3g

Advisory: Graby has stored XSS via iframe srcdoc Attribute in htmLawed Sanitization Config
IDs: GHSA-3h6j-9x8m-rg3g
Record: https://patchnext.com/advisories/ghsa-3h6j-9x8m-rg3g (revision 1, source checked 26 Oct 2026, 14:39 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 2.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: j0k3r/graby 2.5.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist j0k3r/graby: affected <= 2.5.0; fixed in 2.5.1

## Suggested inspection (read-only)
- Packagist j0k3r/graby: 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 j0k3r/graby.
- 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-3h6j-9x8m-rg3g (GitHub-reviewed advisory GHSA-3h6j-9x8m-rg3g lists affected ranges: Packagist j0k3r/graby >=0 <=2.5.0)

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