What is CVE-2026-40564?

CVE-2026-40564 is a medium-severity vulnerability in Apache Flink_kubernetes_operator, classified under Files or Directories Accessible to External Parties. CVSS score: 6.5/10. Published 2026-05-26.

How severe is CVE-2026-40564?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Is CVE-2026-40564 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

SSRF in Apache Flink_kubernetes_operator

CVE-2026-40564

Files or Directories Accessible to External Parties, Server-Side Request Forgery (SSRF) vulnerability in Apache Flink Kubernetes Operator. The FlinkSessionJob jarURI is currently not validated so that it points to user-owned files or addr…

EPSS: 0.001 (17.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

Affected products

Apache Flink_kubernetes_operator
Apache Software Foundation Flink Kubernetes Operator — versions 1.3.0

Weakness classification (CWE)

Public proof-of-concept exploits

oscerd/CVE-2026-40564

References

security@apache.org (vendor-advisory, Mailing List)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2026-40564?: CVE-2026-40564 is a medium-severity vulnerability in Apache Flink_kubernetes_operator, classified under Files or Directories Accessible to External Parties. CVSS score: 6.5/10. Published 2026-05-26.
How severe is CVE-2026-40564?: Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2026-40564 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.