How severe is GHSA-9pq4-5hcf-288c?

No CVSS score has been assigned to GHSA-9pq4-5hcf-288c yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-9pq4-5hcf-288c?

GHSA-9pq4-5hcf-288c affects the following packages: @sveltejs/adapter-vercel (npm). Ecosystems affected: npm.

How do I fix GHSA-9pq4-5hcf-288c?

Update @sveltejs/adapter-vercel to 6.3.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9pq4-5hcf-288c is resolved across your whole dependency graph.

How do I detect GHSA-9pq4-5hcf-288c in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @sveltejs/adapter-vercel. 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-9pq4-5hcf-288c 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-9pq4-5hcf-288c?

O3 pinpoints whether GHSA-9pq4-5hcf-288c 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-9pq4-5hcf-288c actively exploited in the wild?

No public exploit code has been indexed for GHSA-9pq4-5hcf-288c 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-9pq4-5hcf-288c?

GHSA-9pq4-5hcf-288c has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 17th 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-9pq4-5hcf-288c?

GHSA-9pq4-5hcf-288c is classified as CWE-346 (CWE-346). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-9pq4-5hcf-288c published, and has it been updated?

GHSA-9pq4-5hcf-288c was published on February 19, 2026 and was last updated on February 23, 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-9pq4-5hcf-288c: Cache poisoning in @sveltejs/adapter-vercel

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk17th percentile+0.25%

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

📦@sveltejs/adapter-vercel

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

Versions of @sveltejs/adapter-vercel prior to 6.3.2 are vulnerable to cache poisoning. An internal query parameter intended for Incremental Static Regeneration (ISR) is accessible on all routes, allowing an attacker to cause sensitive user-specific responses to be cached and served to other users.

Successful exploitation requires a victim to visit an attacker-controlled link while authenticated.

Existing deployments are protected by Vercel's WAF, but users should upgrade as soon as possible.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@sveltejs/adapter-vercel`	all versions	6.3.2

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @sveltejs/adapter-vercel. 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 @sveltejs/adapter-vercel to 6.3.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9pq4-5hcf-288c 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-9pq4-5hcf-288c 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-9pq4-5hcf-288c. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Versions of `@sveltejs/adapter-vercel` prior to 6.3.2 are vulnerable to cache poisoning. An internal query parameter intended for Incremental Static Regeneration (ISR) is accessible on all routes, allowing an attacker to cause sensitive user-specific responses to be cached and served to other users. Successful exploitation requires a victim to visit an attacker-controlled link while authenticated. Existing deployments are protected by Vercel's WAF, but users should upgrade as soon as possible.

O3 Security · Impact-Aware SCA

Is GHSA-9pq4-5hcf-288c in your dependencies?

O3 detects GHSA-9pq4-5hcf-288c 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

GHSA-9pq4-5hcf-288c