GHSA-q7jf-gf43-6x6p is a medium-severity (CVSS 4.2) CWE-113 vulnerability in hono. A fix is available for hono — see the affected versions and patch details below.
Hono vulnerable to Vary Header Injection leading to potential CORS Bypass
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-q7jf-gf43-6x6p.
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-q7jf-gf43-6x6p 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.
hononpmDescription
Summary
A flaw in the CORS middleware allowed request Vary headers to be reflected into the response, enabling attacker-controlled Vary values and potentially affecting cache behavior.
Details
The middleware previously copied the Vary header from the request when origin was not set to "*". Since Vary is a response header that should only be managed by the server, this could allow an attacker to influence caching behavior or cause inconsistent CORS handling.
Most environments will see impact only when shared caches or proxies rely on the Vary header. The practical effect varies by configuration.
Impact
May cause cache key pollution and inconsistent CORS enforcement in certain setups. No direct confidentiality, integrity, or availability impact in default configurations.
Resolution
Update to the latest patched release. The CORS middleware has been corrected to handle Vary exclusively as a response header.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | hono | all versions | 4.10.3npm install hono@4.10.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for hono, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update hono to 4.10.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-q7jf-gf43-6x6p 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-q7jf-gf43-6x6p can be triaged on real exposure rather than presence alone.
Tailored to GHSA-q7jf-gf43-6x6p. 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-q7jf-gf43-6x6p in your dependencies?
O3 Security finds GHSA-q7jf-gf43-6x6p across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.