GHSA-wm8w-6qjm-cv43 is a high-severity (CVSS 7.5) CWE-524 vulnerability in nuxt. A fix is available for nuxt — see the affected versions and patch details below.
Nuxt runtime payload cache discloses another user's SSR data across users and to unauthenticated clients
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-wm8w-6qjm-cv43.
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.
How urgent is this, really
GHSA-wm8w-6qjm-cv43 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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.
nuxtnpmDescription
Impact
When a page is covered by routeRules cache / swr / isr, Nuxt enables runtime payload extraction and serves /<page>/_payload.json. On affected versions the renderer stored the SSR payload in the shared cache:nuxt:payload storage under a path-only key (no cookie, authorization, or cache.varies dimension) and, on a later payload request, returned the cached entry before route middleware / page guards ran again.
As a result, once any authenticated user warms a protected, cached page, a subsequent GET /<page>/_payload.json from an unauthenticated client or a different authenticated user receives the first user's payload: the full SSR data for that route, including anything loaded via useFetch / useAsyncData (for example /api/me: profile, tenant, billing, token-like values). The HTML response stays correctly varied and protected; only the extracted payload leaks. Both cross-user (A warms, B receives A) and unauthenticated disclosure are exploitable. cache.varies does not mitigate it, because the payload cache ignores varies.
Introduced when runtime payload extraction landed for cached routes (#34410); the regression is specific to the 4.x line, where the runtime cache:nuxt:payload storage was added and the import.meta.prerender gate on the payload-cache read/writes was dropped. The 3.x line shipped the same feature with the gate intact and is not affected.
Patches
Fixed in [email protected]. Runtime payload-cache reads and writes are again confined to prerendering (import.meta.prerender); at runtime, /<page>/_payload.json follows the normal render path so route middleware, routeRules.appMiddleware, and page guards run for the current request. main / v5 and the 3.x line already had this property, so 3.x is not affected.
Workarounds
- Set
experimental.payloadExtraction: false(reporter-validated): the standalone/_payload.jsonendpoint returns 404 and the page still serves a 200 with an inline payload. - Do not apply
cache/swr/isrto authenticated pages that render user-specific SSR data. - As defense-in-depth, require authentication for
/**/_payload.jsonat a proxy / CDN. - After upgrading, purge any CDN / platform cache that may already hold protected payloads.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | nuxt | ≥ 4.4.0&&< 4.5.1 | 4.5.1npm install nuxt@4.5.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nuxt, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update nuxt to 4.5.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-wm8w-6qjm-cv43 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-wm8w-6qjm-cv43 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-wm8w-6qjm-cv43. 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-wm8w-6qjm-cv43 in your dependencies?
O3 Security finds GHSA-wm8w-6qjm-cv43 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.