CVE-2026-84445: gRPC-Go xDS server denial of service via missing headers

CVE-2026-84445 · Severity: high · CVSS 4 · Published 2026-09-14

gRPC-Go is a popular RPC framework used to build distributed applications and microservices. When configured with xDS routing (a service mesh feature), servers crash if they receive HTTP/2 requests missing both the `:authority` and `Host` headers, causing a complete service outage. An attacker who can establish a network connection to the server can trigger this crash remotely.

Technologies: google.golang.org/grpc (Go). Vendors: Go.

Quick answers

Is CVE-2026-84445 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-84445 being exploited in the wild.
How severe is CVE-2026-84445?
High severity, with a CVSS score of 4, published 14 September 2026.
Which products and versions are affected?
google.golang.org/grpc (Go) SEMVER:introduced=0,fixed=1.82.2, SEMVER:introduced=0,fixed=1.82.2,introduced=1.83.0,fixed=1.83.2,introduced=1.84.0-dev,fixed=1.85.0-dev.0.20260825072537-93e31b48545e.
Is there a fix for CVE-2026-84445?
Yes. google.golang.org/grpc (Go): upgrade to 1.82.2, 1.85.0-dev.0.20260825072537-93e31b48545e or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-84445 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-84445?
Check whether you run google.golang.org/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.

How to fix

  • google.golang.org/grpc (Go): upgrade to 1.82.2, 1.85.0-dev.0.20260825072537-93e31b48545e or later
    go get google.golang.org/grpc@v1.85.0-dev.0.20260825072537-93e31b48545e

Technical details

This vulnerability is an uncaught exception (CWE-248) combined with improper array index validation (CWE-129). The root cause lies in the HTTP/2 transport layer which previously accepted requests missing both the `:authority` and `Host` headers. When such a request reaches the xDS routing interceptor, it attempts to look up the request's `:authority` header in an empty slice of authorities, causing an index out of bounds panic. Since the per-RPC goroutine lacks panic recovery, the entire server process terminates. The attack requires successful completion of the transport credentials handshake (TLS/mTLS/ALTS) and HTTP/2 connection establishment before the malicious request can reach the interceptor. On insecure or standard TLS connections, unauthenticated remote attackers can trigger the crash; on mTLS/ALTS, valid transport credentials are required. Patches are available in versions 1.82.2, 1.83.2, and 1.85.0-dev.0.20260825072537-93e31b48545e, which enforce early rejection of requests missing both headers.

Affected products

  • Google gRPC-Go < 1.82.2; 1.83.0 - 1.83.1; 1.84.0-dev - < 1.85.0-dev.0.20260825072537-93e31b48545e

Identifiers

  • CVE-2026-84445
  • GHSA-2v4p-qf9q-27wj
  • GO-2026-6443

Timeline

  • 2026-08-25: disclosed
  • 2026-08-25: patched: Patches released for versions 1.82.2, 1.83.2, and 1.85.0-dev branch
  • 2026-09-08: advisory

References

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