How severe is GHSA-g2g4-47gv-p72v?

GHSA-g2g4-47gv-p72v has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-g2g4-47gv-p72v?

GHSA-g2g4-47gv-p72v affects the following packages: cryptpad (npm). Ecosystems affected: npm.

How do I fix GHSA-g2g4-47gv-p72v?

No patched version of cryptpad has shipped for GHSA-g2g4-47gv-p72v yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

How do I detect GHSA-g2g4-47gv-p72v in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for cryptpad. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-g2g4-47gv-p72v if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-g2g4-47gv-p72v?

O3 pinpoints whether GHSA-g2g4-47gv-p72v is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-g2g4-47gv-p72v actively exploited in the wild?

No public exploit code has been indexed for GHSA-g2g4-47gv-p72v 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 type of vulnerability is GHSA-g2g4-47gv-p72v?

GHSA-g2g4-47gv-p72v is classified as Cross-site Scripting (XSS) (CWE-79), CWE-116 (CWE-116). These weakness types 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-g2g4-47gv-p72v published, and has it been updated?

GHSA-g2g4-47gv-p72v was published on May 26, 2026 and was last updated on June 9, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

GHSA-g2g4-47gv-p72v

MEDIUM

CryptPad has a Sanitizer Bypass in Diffmarked.js that Allows Arbitrary HTML Injection and Potential XSS

Also known asCVE-2026-26028

Published

May 26, 2026

Updated

Jun 9, 2026

Affected

1 pkg

Patched

None yet

Exploits

None indexed

Blast Radius

1 pkg affected

📦cryptpad

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

Description

Summary

CryptPad’s HTML sanitizer in Diffmarked.js can be bypassed due to incomplete filtering of restricted tags. Because the sanitizer only validates the src attribute of <iframe> <video>, and <audio> elements, and does not restrict other attributes, an attacker can inject arbitrary HTML through srcdoc. This completely defeats CryptPad’s intended bounce sandboxing and allows link injection or other interactive content inside user-controlled documents.

Details

The sanitizer defines forbidden and restricted tags but treats <iframe> as “restricted” instead of “forbidden”:

https://github.com/cryptpad/cryptpad/blob/0dd3c1f53d56dffb06651b86ead6b9b387920173/www/common/diffMarked.js#L403-L407 The actual enforcement only checks the src attribute, nothing else:

https://github.com/cryptpad/cryptpad/blob/0dd3c1f53d56dffb06651b86ead6b9b387920173/www/common/diffMarked.js#L445-L449

Because only src is validated, adding a benign blob: src but malicious srcdoc results in unrestricted rendering.

PoC

An attacker can embed arbitrary HTML, including clickable external links, images, or interactive content, completely bypassing CryptPad’s bounce mechanism and sanitization:

<iframe src=blob: srcdoc="<a href=https://attacker.com target=_blank>CLICK ME</a>"></iframe>

Although CSP is strict, CryptPad exposes several same-origin gadgets that can execute attacker-controlled code.

For example, jscolor.js dynamically evaluates user-provided options: https://github.com/cryptpad/cryptpad/blob/0dd3c1f53d56dffb06651b86ead6b9b387920173/www/common/jscolor.js#L65-L71

Impact

Sanitizer bypass, HTML injection and potentially XSS.

Affected Packages

1 total

Ecosystem	Package	Vulnerable range	Fix
📦npm	`cryptpad`	all versions	No fix

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for cryptpad. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of cryptpad has shipped for GHSA-g2g4-47gv-p72v yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-g2g4-47gv-p72v is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-g2g4-47gv-p72v. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary CryptPad’s HTML sanitizer in Diffmarked.js can be bypassed due to incomplete filtering of restricted tags. Because the sanitizer only validates the src attribute of `<iframe>` `<video>`, and `<audio>` elements, and does not restrict other attributes, an attacker can inject arbitrary HTML through srcdoc. This completely defeats CryptPad’s intended bounce sandboxing and allows link injection or other interactive content inside user-controlled documents. ### Details The sanitizer defines forbidden and restricted tags but treats <iframe> as “restricted” instead of “forbidden”: https

O3 Security · Impact-Aware SCA

Is GHSA-g2g4-47gv-p72v in your dependencies?

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