etcd: Watch API authorization bypass via open-ended range requests
Exact source revision recorded 24 Oct 2026 13:19:41 UTC. It does not establish the source's current position. Latest evidence.
osv · GHSA-xg4h-6gfc-h4m8
Published### Impact _What kind of vulnerability is it? Who is impacted?_ A user granted READ permission on a single, exact key can use the Watch gRPC API with `clientv3.WithFromKey()` (an open-ended, "from this key to the end of the keyspace" watch) to receive watch events for every key lexicographically greater than or equal to their permitted key — not just the one key they were granted. This is an authorization bypass in etcd's RBAC enforcement for the Watch API; Range/Get and DeleteRange requests are not affected. It only affects clusters with authentication enabled — clusters running without auth already allow unrestricted read access. ### Patches _Has the problem been patched? What versions should users upgrade to?_ This vulnerability is patched in the following versions: - etcd 3.7.1 - etcd 3.6.14 - etcd 3.5.33 ### Workarounds _Is there a way for users to fix or remediate the vulnerability without upgrading?_ If upgrading is not immediately possible, the following mitigations reduce exposure: - Audit READ grants. Any READ grant — even on one key — can be leveraged via Watch to read everything after it. Review who holds READ permissions and revoke/tighten any you wouldn't trust with full read access. - Restrict network access. Limit which hosts can reach etcd's client (gRPC) port via firewall rules or network policy, reducing who can attempt exploitation. ### Reporter - Luis Toro ([@lobuhi](https://github.com/lobuhi) on Github) - Anthropic and Adam Korczynski ([@AdamKorcz](https://github.com/AdamKorcz) on Github)
- Source published
- 24 Jul 2026 22:38:22 UTC
- Source modified
- 10 Sep 2026 03:50:53 UTC
- Observed here
- 24 Oct 2026 13:19:41 UTC
- Source terms
- GitHub Advisory Database · CC-BY-4.0
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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.
CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Publisher rating · HIGH