oRPC: Vary Header Injection in CORS Plugin leading to potential Cache/CORS Bypass
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.
Summary
oRPC is an tool that helps build APIs that are end-to-end type-safe and adhere to OpenAPI standards. Prior to 1.14.8, the @orpc/server CORS plugin in packages/server/src/plugins/cors.ts copies a client's incoming Vary request header into the response instead of controlling Vary as a response-only header and using Origin for request-origin variation. In deployments behind a shared cache, CDN, or reverse proxy that keys responses using Vary, a client can inject arbitrary variation values, pollute cache keys, and cause inconsistent CORS enforcement for other clients. Default non-cached configurations have no established direct confidentiality, integrity, or availability impact. This issue is fixed in version 1.14.8.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| middleapi | orpc | before 1.14.8 | 1.14.8 | Patch available | CNA |
| — | @orpc/server (npm) | before 1.14.8 | 1.14.8 | Patch available | GHSA-j9v4-rhgr-4m5f |
- orpc Vendormiddleapi Affected before 1.14.8 Fixed in 1.14.8 Patch available CNA
- @orpc/server (npm) Vendor— Affected before 1.14.8 Fixed in 1.14.8 Patch available GHSA-j9v4-rhgr-4m5f
Remediation
- Fix · CNA orpc (middleapi) Fixed in 1.14.8
- Fix · GHSA-j9v4-rhgr-4m5f @orpc/server (npm) Fixed in 1.14.8 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-77360
- 2026-10-03 Alias added: GHSA-j9v4-rhgr-4m5f
References
Other 6
- https://github.com/middleapi/orpc/security/advisories/GHSA-j9v4-rhgr-4m5f
- https://github.com/middleapi/orpc/issues/1661
- https://github.com/middleapi/orpc/pull/1662
- https://github.com/middleapi/orpc/commit/daabded122a89d323357c4c401e879701864cb2f
- https://github.com/middleapi/orpc/releases/tag/v1.14.8
- https://github.com/middleapi/orpc
More middleapi vulnerabilities
- TI-2026-66040 @orpc/zod: Prototype injection in smart coercion CVSS 3.1MEDIUM 6.5
- TI-2026-66014 @orpc/json-schema: Prototype injection in smart coercion CVSS 3.1MEDIUM 6.5
Sources
- CVE-2026-77360 · CVE Program
- CVE-2026-77360 · NVD
- FIRST EPSS
- GHSA-j9v4-rhgr-4m5f · GitHub Advisory Database · CC BY 4.0
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