How severe is GHSA-wf42-42fg-fg84?

No CVSS score has been assigned to GHSA-wf42-42fg-fg84 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-wf42-42fg-fg84?

GHSA-wf42-42fg-fg84 affects the following packages: @nestjs/platform-fastify (npm). Ecosystems affected: npm.

How do I fix GHSA-wf42-42fg-fg84?

Update @nestjs/platform-fastify to 11.1.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-wf42-42fg-fg84 is resolved across your whole dependency graph.

How do I detect GHSA-wf42-42fg-fg84 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @nestjs/platform-fastify. 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-wf42-42fg-fg84 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-wf42-42fg-fg84?

O3 pinpoints whether GHSA-wf42-42fg-fg84 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-wf42-42fg-fg84 actively exploited in the wild?

No public exploit code has been indexed for GHSA-wf42-42fg-fg84 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-wf42-42fg-fg84?

GHSA-wf42-42fg-fg84 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 26th 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-wf42-42fg-fg84?

GHSA-wf42-42fg-fg84 is classified as CWE-670 (CWE-670). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-wf42-42fg-fg84 published, and has it been updated?

GHSA-wf42-42fg-fg84 was published on March 17, 2026 and was last updated on March 20, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

GHSA-wf42-42fg-fg84: Nest Fastify HEAD Request Middleware Bypass

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk26th percentile+0.30%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.

@nestjs/platform-fastifynpm

1.2Mdownloads / week

Description

Impact

In a NestJS application using @nestjs/platform-fastify, GET middleware can be bypassed because Fastify automatically redirects HEAD requests to the corresponding GET handlers (if they exist).

As a result:

Middleware will be completely skipped.
The HTTP response won't include a body (since the response is truncated when redirecting a HEAD request to a GET handler).
The actual handler will still be executed.

Patches

Fixed in @nestjs/[email protected]

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@nestjs/platform-fastify`	all versions	11.1.16

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @nestjs/platform-fastify. 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 @nestjs/platform-fastify to 11.1.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-wf42-42fg-fg84 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 GHSA-wf42-42fg-fg84 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-wf42-42fg-fg84. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact In a NestJS application using `@nestjs/platform-fastify`, GET middleware can be bypassed because Fastify automatically redirects HEAD requests to the corresponding GET handlers (if they exist). As a result: - Middleware will be completely skipped. - The HTTP response won't include a body (since the response is truncated when redirecting a HEAD request to a GET handler). - The actual handler will still be executed. ### Patches Fixed in `@nestjs/[email protected]`

O3 Security · Impact-Aware SCA

Is GHSA-wf42-42fg-fg84 in your dependencies?

O3 detects GHSA-wf42-42fg-fg84 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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GHSA-wf42-42fg-fg84