Core infra (etcd) used with Kubernetes; exploitation could disrupt clusters across many environments. Patch available.
CVE-2026-33413
Auth bypass in etcd gRPC API enables topology discovery, DoS, and lease/compaction abuse.
Is CVE-2026-33413 being exploited?
Not confirmed. CVE-2026-33413 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.25% probability of exploitation in the next 30 days.
How severe is CVE-2026-33413?
CVE-2026-33413 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-33413?
Yes. A fix has been recorded for CVE-2026-33413. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-33413 affect?
CVE-2026-33413 affects etcd (versions < 3.4.42, 3.5.28, 3.6.9), Kubernetes clusters with etcd gRPC exposure. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-33413?
Upgrade etcd to patched releases; restrict gRPC exposure (mTLS).
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated gRPC calls can reveal cluster topology, disrupt ops via Alarm, Lease misuse, and trigger compaction leading to data loss.
Patch when possible
- affected>= 3.6.0-alpha.0 and < 3.6.9
- affected>= 3.5.0-alpha.0 and < 3.5.28
- affected< 3.4.42
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.