How severe is GHSA-j9v4-rhgr-4m5f?

No CVSS score has been assigned to GHSA-j9v4-rhgr-4m5f yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-j9v4-rhgr-4m5f?

GHSA-j9v4-rhgr-4m5f affects the following packages: @orpc/server (npm). Ecosystems affected: npm.

How do I fix GHSA-j9v4-rhgr-4m5f?

Update @orpc/server to 1.14.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-j9v4-rhgr-4m5f is resolved across your whole dependency graph.

How do I detect GHSA-j9v4-rhgr-4m5f in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @orpc/server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-j9v4-rhgr-4m5f 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-j9v4-rhgr-4m5f?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-j9v4-rhgr-4m5f can be triaged on real exposure rather than presence alone.

Is GHSA-j9v4-rhgr-4m5f actively exploited in the wild?

No public exploit code has been indexed for GHSA-j9v4-rhgr-4m5f 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-j9v4-rhgr-4m5f?

GHSA-j9v4-rhgr-4m5f has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 48th 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-j9v4-rhgr-4m5f?

GHSA-j9v4-rhgr-4m5f is classified as CWE-113 (CWE-113). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-j9v4-rhgr-4m5f published, and has it been updated?

GHSA-j9v4-rhgr-4m5f was published on September 17, 2026 and was last updated on September 17, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

GHSA-j9v4-rhgr-4m5f — @orpc/server

Fix: middleapi/orpc#1662

GHSA-j9v4-rhgr-4m5f is a CWE-113 vulnerability in @orpc/server. A fix is available for @orpc/server — see the affected versions and patch details below.

oRPC: Vary Header Injection in CORS Plugin leading to potential Cache/CORS Bypass

Also known asCVE-2026-77360

Published

Sep 17, 2026

Updated

Sep 17, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 18, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for GHSA-j9v4-rhgr-4m5f.

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs48th percentile — riskier than 48% of all scored CVEsHighest risk

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

1 pkg affected

📦@orpc/server

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

Summary

A flaw in the CORS plugin allowed the incoming request's Vary header to be reflected into the response, letting a client influence a header that should be controlled solely by the server.

Details

The CORS plugin previously copied the request's Vary header directly onto the response instead of treating Vary as a response-only header. Because Vary tells downstream caches and proxies how to key their cached responses, this allowed a client to inject arbitrary values into the response's Vary header, potentially distorting cache-key behavior in shared caches/CDNs sitting in front of an oRPC server and leading to inconsistent CORS enforcement for other clients.

Practical impact is limited to deployments where a shared cache or reverse proxy keys on the Vary header; the real-world effect depends on the caching layer's configuration.

Impact

May cause cache key pollution and inconsistent CORS enforcement in setups that rely on shared/edge caches keying on Vary. No direct confidentiality, integrity, or availability impact in default (non-cached) configurations.

Resolution

Update @orpc/server (and any other @orpc/* packages bundling the CORS plugin) to 1.14.8. The CORS plugin now derives Vary exclusively from the response, appending Origin and preserving existing values instead of reflecting request headers.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@orpc/server`	all versions	1.14.8`npm install @orpc/server@1.14.8`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @orpc/server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @orpc/server to 1.14.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-j9v4-rhgr-4m5f 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-j9v4-rhgr-4m5f can be triaged on real exposure rather than presence alone.

Tailored to GHSA-j9v4-rhgr-4m5f. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary A flaw in the CORS plugin allowed the incoming request's `Vary` header to be reflected into the response, letting a client influence a header that should be controlled solely by the server. ### Details The CORS plugin previously copied the request's `Vary` header directly onto the response instead of treating `Vary` as a response-only header. Because `Vary` tells downstream caches and proxies how to key their cached responses, this allowed a client to inject arbitrary values into the response's `Vary` header, potentially distorting cache-key behavior in shared caches/CDNs sitting

O3 Security · Impact-Aware SCA

Is GHSA-j9v4-rhgr-4m5f in your dependencies?

O3 Security finds GHSA-j9v4-rhgr-4m5f across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works