code16 Sharp vulnerable to stored XSS via iframe srcdoc Attribute

Exploitation

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

CVSS

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

EPSS

• CVE-2026-61823: 0.21% estimated exploitation activity in the next 30 days; percentile 11.29 (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 A Stored Cross-Site Scripting (XSS) vulnerability exists in the rich text editor due to improper sanitization of the srcdoc attribute on <iframe elements. While the underlying Symfony HtmlSanitizer correctly HTML-encodes special characters inside the attribute value (e.g., converting <script to &lt;script&gt;), the HTML specification mandates that browsers automatically decode HTML entities inside attribute values before processing them. As a result, any encoded JavaScript inside a srcdoc attribute is evaluated and executed as live HTML/JS in the context of the iframe when the page is rendered. An attacker with permissions to edit an Editor field can inject malicious scripts to target other users viewing the content. Potential impacts include: - Session Hijacking (stealing admin session cookies via document.cookie) - Account Takeover & Privilege Escalation (e.g., a low-privileged editor triggering actions as an Administrator) - Admin panel data theft Patches The vulnerability…

Published by the source

25 Sep 2026, 15:02 UTC

Last modified by the source

25 Sep 2026, 15:15 UTC

Source last checked

26 Oct 2026, 14:53 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-qxg3-46rw-79j8

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-qxg3-46rw-79j8

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# Patch Next advisory brief: CVE-2026-61823

Advisory: code16 Sharp vulnerable to stored XSS via iframe srcdoc Attribute
IDs: CVE-2026-61823, GHSA-qxg3-46rw-79j8
Record: https://patchnext.com/advisories/cve-2026-61823 (revision 2, source checked 26 Oct 2026, 14:53 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: code16/sharp 9.22.5. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist code16/sharp: affected < 9.22.5; fixed in 9.22.5

## Suggested inspection (read-only)
- Packagist code16/sharp: 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 code16/sharp.
- 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://osv.dev/vulnerability/GHSA-qxg3-46rw-79j8 (OSV record GHSA-qxg3-46rw-79j8 lists affected ranges: Packagist code16/sharp >=0 <9.22.5 (fixed))
- Verified: https://github.com/advisories/GHSA-qxg3-46rw-79j8 (GitHub-reviewed advisory GHSA-qxg3-46rw-79j8 lists affected ranges: Packagist code16/sharp >=0 <9.22.5)

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