CVE-2026-73499

etcd: Watch API authorization bypass via open-ended range requests

Description

etcd is a distributed key-value store for the data of a distributed system. Prior to versions 3.5.33, 3.6.14, and 3.7.1, a user granted READ permission on a single exact key can use the Watch gRPC API with clientv3.WithFromKey() to receive watch events for every key lexicographically greater than or equal to the permitted key. In server/etcdserver/api/v3rpc/watch.go, the open-ended RangeEnd sentinel is rewritten before the RBAC permission check in server/auth/range_perm_cache.go function isRangeOpPermitted, causing the request to be treated as an exact-key watch. Range/Get and DeleteRange requests are not affected, and the issue affects only clusters with authentication enabled. This issue is fixed in versions 3.5.33, 3.6.14, and 3.7.1.

Scores

Weaknesses (CWE)

• CWE-863

Advisories

• GHSA-xg4h-6gfc-h4m8 — etcd: Watch API authorization bypass via open-ended range requests
• GO-2026-6114 — Watch API authorization bypass in go.etcd.io/etcd/server/v3

European references

• ENISA EUVD · EUVD-2026-57641
• GCVE · GCVE-0-2026-73499

Affected products

References

• https://github.com/etcd-io/etcd/security/advisories/GHSA-xg4h-6gfc-h4m8
• https://github.com/etcd-io/etcd/commit/6643f80602461a6095c9b294b6512fd9719bef41
• https://github.com/etcd-io/etcd/commit/7cf71ec9e2ec54230a5454392fa4ffd4574b41ed
• https://github.com/etcd-io/etcd/commit/afeaa624da19085b47fb5ccc7c22a8c421bc2eae
• https://github.com/etcd-io/etcd/commit/e863b001bbf3367003a543aa3099db9892134cd7
• https://github.com/etcd-io/etcd/releases/tag/v3.5.33
• https://github.com/etcd-io/etcd/releases/tag/v3.6.14
• https://github.com/etcd-io/etcd/releases/tag/v3.7.1

Sources