GHSA-6wqw-2p9w-4vw4
MEDIUMHono cache middleware ignores "Cache-Control: private" leading to Web Cache Deception
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.
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
hononpmDescription
Summary
Cache Middleware contains an information disclosure vulnerability caused by improper handling of HTTP cache control directives. The middleware does not respect standard cache control headers such as Cache-Control: private or Cache-Control: no-store, which may result in private or authenticated responses being cached and subsequently exposed to unauthorized users.
Details
The vulnerability exists in the cache decision logic of Cache Middleware. When determining whether a response should be cached, the middleware does not take HTTP cache control semantics into account and may cache responses that are explicitly marked as private by the application. While some runtimes, such as Cloudflare Workers, enforce cache control restrictions at the platform level, other runtimes including Deno, Bun, and Node.js rely on the middleware’s behavior. As a result, applications running on these runtimes may unintentionally cache sensitive responses.
Impact
This issue can lead to Web Cache Deception and information disclosure. If an authenticated user accesses an endpoint that returns user-specific or sensitive data and the response is cached despite being marked as private, subsequent unauthenticated requests may receive the cached response. This may result in the exposure of personally identifiable information or session-related data. The impact is limited to applications that use the hono/cache middleware and rely on it to correctly honor HTTP cache control directives.
Affected Components
- Cache Middleware
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | hono | all versions | 4.11.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for hono. 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 hono to 4.11.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6wqw-2p9w-4vw4 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-6wqw-2p9w-4vw4 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-6wqw-2p9w-4vw4. 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-6wqw-2p9w-4vw4 in your dependencies?
O3 detects GHSA-6wqw-2p9w-4vw4 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.