GHSA-j62c-4x62-9r35 — @sveltejs/kit
Fix: sveltejs/kit@d9ae9b0GHSA-j62c-4x62-9r35 is a CWE-248 vulnerability in @sveltejs/kit. A fix is available for @sveltejs/kit — see the affected versions and patch details below.
SvelteKit is vulnerable to denial of service and possible SSRF when using prerendering
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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-j62c-4x62-9r35.
EPSS Exploitation Probability
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.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@sveltejs/kitnpm@sveltejs/adapter-nodenpmDescription
Summary
Versions of SvelteKit are vulnerable to a server side request forgery (SSRF) and denial of service (DoS) under certain conditions.
Details
Affected versions from 2.44.0 onwards are vulnerable to DoS if:
- your app has at least one prerendered route (
export const prerender = true)
Affected versions from 2.19.0 onwards are vulnerable to DoS and SSRF if:
- your app has at least one prerendered route (
export const prerender = true) - AND you are using
adapter-nodewithout a configuredORIGINenvironment variable, and you are not using a reverse proxy that implements Host header validation
Impact
The DoS causes the running server process to end.
The SSRF allows access to internal services that can be reached without authentication when fetched from SvelteKit's server runtime.
It is also possible to obtain an SXSS via cache poisoning, by forcing a potential CDN to cache an XSS returned by the attacker's server (the latter being able to specify the cache-control of their choice).
Credits
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @sveltejs/kit | ≥ 2.19.0&&< 2.49.5 | 2.49.5npm install @sveltejs/kit@2.49.5 |
| 📦npm | @sveltejs/adapter-node | ≥ 5.4.1&&< 5.5.1 | 5.5.1npm install @sveltejs/adapter-node@5.5.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @sveltejs/kit, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @sveltejs/kit to 2.49.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-j62c-4x62-9r35 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-j62c-4x62-9r35 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-j62c-4x62-9r35. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-j62c-4x62-9r35 in your dependencies?
O3 Security finds GHSA-j62c-4x62-9r35 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.