What is GHSA-qxg3-46rw-79j8?

### Impact A Stored Cross-Site Scripting (XSS) vulnerability exists in the rich text editor due to improper sanitization of the srcdoc attribute on elements. While the underlying Symfony HtmlSanitizer correctly HTML-encodes special characters inside the attribute value (e.g., converting to <script>), 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 pa

How severe is GHSA-qxg3-46rw-79j8?

GHSA-qxg3-46rw-79j8 has a CVSS score of 7.3/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-qxg3-46rw-79j8?

GHSA-qxg3-46rw-79j8 affects the following packages: code16/sharp (Packagist). Ecosystems affected: Packagist.

How do I fix GHSA-qxg3-46rw-79j8?

Update code16/sharp to 9.22.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-qxg3-46rw-79j8 is resolved across your whole dependency graph.

How do I detect GHSA-qxg3-46rw-79j8 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for code16/sharp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-qxg3-46rw-79j8 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is GHSA-qxg3-46rw-79j8 actively exploited in the wild?

No public exploit code has been indexed for GHSA-qxg3-46rw-79j8 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 GHSA-qxg3-46rw-79j8?

GHSA-qxg3-46rw-79j8 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 11th 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.

What type of vulnerability is GHSA-qxg3-46rw-79j8?

GHSA-qxg3-46rw-79j8 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was GHSA-qxg3-46rw-79j8 published, and has it been updated?

GHSA-qxg3-46rw-79j8 was published on September 25, 2026 and was last updated on September 25, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘

🐘 Packagist

Not in CISA KEV

HIGH severity

code16 Sharp vulnerable to stored XSS via iframe srcdoc AttributeGHSA-qxg3-46rw-79j8

HIGHFix: code16/sharp@ec509a2

GHSA-qxg3-46rw-79j8 is a high-severity (CVSS 7.3) Cross-site Scripting (XSS) vulnerability in code16/sharp. A fix is available for code16/sharp — see the affected versions and patch details below.

Also known asCVE-2026-61823

Published

Sep 25, 2026

Updated

Sep 25, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 24, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-qxg3-46rw-79j8.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs11th percentile — riskier than 11% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

GHSA-qxg3-46rw-79j8 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 394,803 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

🐘code16/sharp

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

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 <script>), 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 has been patched in version v9.22.5.

The fix explicitly removes srcdoc from the list of allowed iframe attributes in src/Utils/Sanitization/FormatsSanitizedValue.php.

Workarounds

Users who cannot upgrade immediately can manually sanitize all content of editor fields to strip srcdoc attributes.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`code16/sharp`	all versions	9.22.5`composer require code16/sharp:^9.22.5`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for code16/sharp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update code16/sharp to 9.22.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-qxg3-46rw-79j8 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

### 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 <script>), 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 pa