How severe is CVE-2026-40201?

CVE-2026-40201 has a CVSS score of 5.4/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2026-40201?

CVE-2026-40201 affects the following packages: @diplodoc/search-extension (npm). Ecosystems affected: npm.

How do I fix CVE-2026-40201?

Update @diplodoc/search-extension to 3.0.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-40201 is resolved across your whole dependency graph.

How do I detect CVE-2026-40201 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @diplodoc/search-extension. 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 CVE-2026-40201 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 CVE-2026-40201?

O3 pinpoints whether CVE-2026-40201 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 CVE-2026-40201 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-40201 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.

When was CVE-2026-40201 published, and has it been updated?

CVE-2026-40201 was published on May 1, 2026 and was last updated on August 4, 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

CVE-2026-40201

MEDIUM

CVE-2026-40201 is a medium-severity (CVSS 5.4) vulnerability in @diplodoc/search-extension. O3 Security confirms whether CVE-2026-40201 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

@diplodoc/search-extension allows stored XSS via Markdown file title

Also known asGHSA-rjmp-rwj4-mv82

Published

May 1, 2026

Updated

Aug 4, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Blast Radius

1 pkg affected

📦@diplodoc/search-extension

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

@diplodoc/search-extension 1.0.0 through 3.x before 3.0.3 allows stored XSS via the title in a .md file.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@diplodoc/search-extension`	≥ 1.0.0&&< 3.0.5	3.0.5

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @diplodoc/search-extension. 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.
Fix
Update @diplodoc/search-extension to 3.0.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-40201 is resolved across your whole dependency graph.
Workarounds
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 CVE-2026-40201 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 CVE-2026-40201. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

@diplodoc/search-extension 1.0.0 through 3.x before 3.0.3 allows stored XSS via the title in a .md file.

O3 Security · Impact-Aware SCA

Is CVE-2026-40201 in your dependencies?

O3 detects CVE-2026-40201 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works