# CVE-2026-73499: etcd authorization bypass in Watch gRPC API

Source: https://junglewise.ai/threats/cve-2026-73499-etcd-authorization-bypass-in-watch-grpc-api  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-12. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-73499 · Severity: medium · CVSS 4 · Published 2026-08-12

etcd is a distributed key-value database used to store critical configuration and state for distributed systems like Kubernetes. A flaw in the authentication checks allows a user with read permission for a single key to view all data lexicographically after that key, effectively bypassing access controls in authenticated clusters.

Technologies: [go.etcd.io/etcd/v3 (Go)](https://junglewise.ai/threats/technologies/go-etcd-io-etcd-v3). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-73499 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-73499 being exploited in the wild.

**How severe is CVE-2026-73499?** Medium severity, with a CVSS score of 4, published 12 August 2026.

**Which products and versions are affected?** go.etcd.io/etcd/server/v3 (Go) SEMVER:introduced=0,fixed=3.5.33,introduced=3.6.0,fixed=3.6.14,introduced=3.7.0-alpha.0,fixed=3.7.1; go.etcd.io/etcd/v3 (Go) SEMVER:introduced=3.7.0-alpha.0,fixed=3.7.1.

**Is there a fix for CVE-2026-73499?** Yes. go.etcd.io/etcd/server/v3 (Go): upgrade to 3.7.1 or later; go.etcd.io/etcd/v3 (Go): upgrade to 3.7.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-73499 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-73499?** Check whether you run go.etcd.io/etcd/server/v3 (Go) or go.etcd.io/etcd/v3 (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

- go.etcd.io/etcd/server/v3 (Go): upgrade to 3.7.1 or later

  ```sh
  go get go.etcd.io/etcd/server/v3@v3.7.1
  ```

- go.etcd.io/etcd/v3 (Go): upgrade to 3.7.1 or later

  ```sh
  go get go.etcd.io/etcd/v3@v3.7.1
  ```


## Technical details

An authorization bypass vulnerability exists in the Watch gRPC API (server/etcdserver/api/v3rpc/watch.go) where an open-ended RangeEnd sentinel is rewritten before the RBAC permission check in server/auth/range_perm_cache.go function isRangeOpPermitted. This causes range-based watch requests using clientv3.WithFromKey() to bypass permission checks and be treated as exact-key watches, allowing attackers with READ permission on one key to receive watch events for all keys lexicographically greater than or equal to that key. The vulnerability requires authentication to be enabled on the cluster and affects only the Watch API; Range/Get and DeleteRange operations are unaffected. Fixed in versions 3.5.33, 3.6.14, and 3.7.1.

## Affected products

- etcd etcd before 3.5.33, 3.6.14, and 3.7.1

## Identifiers

- CVE-2026-73499
- GHSA-xg4h-6gfc-h4m8
- GO-2026-6114

## Timeline

- 2026-08-12: disclosed: Public disclosure via NVD
- 2026-08-12: patched: Fixed in versions 3.5.33, 3.6.14, and 3.7.1

## References

- [https://github.com/etcd-io/etcd/commit/6643f80602461a6095c9b294b6512fd9719bef41](https://github.com/etcd-io/etcd/commit/6643f80602461a6095c9b294b6512fd9719bef41)
- [https://github.com/etcd-io/etcd/commit/7cf71ec9e2ec54230a5454392fa4ffd4574b41ed](https://github.com/etcd-io/etcd/commit/7cf71ec9e2ec54230a5454392fa4ffd4574b41ed)

## Related threats

- [etcd TLS listener denial of service via connection exhaustion](https://junglewise.ai/threats/cve-2026-73500-etcd-tls-listener-denial-of-service-via-connection-exhaustion)
- [etcd RBAC authorization bypass in transaction operations](https://junglewise.ai/threats/cve-2026-44283-etcd-rbac-authorization-bypass-in-transaction-operations)
- [GO-2026-4808 - Nested etcd transactions bypass RBAC authorization checks in go.etcd.io/etcd](https://junglewise.ai/threats/cve-2026-33343-etcd-nested-etcd-transactions-bypass-rbac-authorization-checks)
- [GO-2026-4806 - Authorization bypasses in multiple APIs in go.etcd.io/etcd](https://junglewise.ai/threats/cve-2026-33413-etcd-authorization-bypasses-in-multiple-apis)
- [GO-2024-2528 - Etcd Gateway TLS endpoint validation only confirms TCP reachability in go.etcd.io/etcd](https://junglewise.ai/threats/go-2024-2528-etcd-gateway-tls-endpoint-validation-only-confirms-tcp-0788e9d2)