# gRPC-Go auth bypass and DoS in xDS RBAC and HTTP/2 transport

Source: https://junglewise.ai/threats/grpc-go-auth-bypass-and-dos-in-xds-rbac-and-http-2-transport-878951d5  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-21. Updated: 2026-07-21  
License: CC BY 4.0 with a link back

Severity: high · CVSS 8.8 · Published 2026-07-21

gRPC-Go, a popular framework for building high-performance services, is affected by multiple vulnerabilities in its authorization and transport components. These flaws could allow unauthorized users to bypass security policies and access restricted data, or enable attackers to crash the server and disrupt operations through denial-of-service attacks. Organizations using gRPC-Go with xDS-based security policies or exposed to public internet traffic should update to the latest version to maintain service availability and data integrity.

Technologies: [google.golang.org/grpc (Go)](https://junglewise.ai/threats/technologies/google-golang-org-grpc). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [Grpc](https://junglewise.ai/threats/vendors/grpc).

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** High severity, with a CVSS score of 8.8, published 21 July 2026.

**Which products and versions are affected?** google.golang.org/grpc (Go) < 1.82.1; gRPC-Go < 1.82.1.

**Is there a fix for This vulnerability?** A patch was published on 2026-07-15: Fixes merged into master and v1.82.x branch Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is This vulnerability attacked?** It is attacked over the network, in a software library.

**Am I affected?** Check whether you run google.golang.org/grpc (Go) or gRPC-Go at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

gRPC-Go contains three distinct vulnerabilities: 1) An authorization bypass in the xDS RBAC engine where 'Metadata' and 'RequestedServerName' matchers were silently ignored, potentially causing policies to fail-open. 2) A Denial of Service (DoS) via HTTP/2 Rapid Reset mitigation bypass, where client-initiated stream resets (RST_STREAM) following HEADERS frames could bypass control buffer thresholds, leading to high CPU consumption. 3) A server panic (CWE-248) in the xDS RBAC engine triggered by 'NOT' rules wrapping unsupported fields like 'SourcedMetadata'. These issues are addressed in version 1.82.1 by enforcing control buffer limits and correctly translating previously unsupported RBAC matchers.

## Affected products

- gRPC grpc-go < 1.82.1

## Timeline

- 2026-07-15: patched: Fixes merged into master and v1.82.x branch
- 2026-07-21: advisory: GitHub Advisory GHSA-hrxh-6v49-42gf published

## References

- [https://github.com/grpc/grpc-go/security/advisories/GHSA-hrxh-6v49-42gf](https://github.com/grpc/grpc-go/security/advisories/GHSA-hrxh-6v49-42gf)
- [https://github.com/grpc/grpc-go/pull/9236](https://github.com/grpc/grpc-go/pull/9236)
- [https://github.com/grpc/grpc-go/commit/4ea465d4ab98013f72a142fe0fc89c19770b2935](https://github.com/grpc/grpc-go/commit/4ea465d4ab98013f72a142fe0fc89c19770b2935)
- [https://github.com/grpc/grpc-go/releases/tag/v1.82.1](https://github.com/grpc/grpc-go/releases/tag/v1.82.1)
- [https://api.github.com/repos/grpc/grpc-go/security-advisories/GHSA-hrxh-6v49-42gf](https://api.github.com/repos/grpc/grpc-go/security-advisories/GHSA-hrxh-6v49-42gf)

## Related threats

- [gRPC-Go xDS server denial of service via missing headers](https://junglewise.ai/threats/cve-2026-84445-grpc-go-xds-server-denial-of-service-via-missing-headers)
- [gRPC-Go heap memory exhaustion via HTTP/2 DATA frame fragmentation](https://junglewise.ai/threats/cve-2026-84304-grpc-go-heap-memory-exhaustion-via-http-2-data-frame)
- [gRPC-Go xDS RBAC HTTP filter bypass via case-sensitive header matching](https://junglewise.ai/threats/cve-2026-84303-grpc-go-xds-rbac-http-filter-bypass-via-case-sensitive-header)
- [GO-2026-6061 - Vulnerabilities in the xDS RBAC authorization engine and the HTTP/2 transport server implementation in…](https://junglewise.ai/threats/go-2026-6061-vulnerabilities-in-the-xds-rbac-authorization-engine-and-2c07d92a)
- [gRPC gRPC-Go authorization bypass in HTTP/2 path validation](https://junglewise.ai/threats/cve-2026-33186-grpc-grpc-go-authorization-bypass-in-http-2-path-validation)