How severe is CVE-2026-40564?

CVE-2026-40564 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-40564 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-40564?

CVE-2026-40564 affects Apache Flink Kubernetes Operator. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-40564?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-40564 have an EU (EUVD) identifier?

Yes. CVE-2026-40564 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31846.

When was CVE-2026-40564 published?

CVE-2026-40564 was published on 2026-05-26 and last updated on 2026-06-17.

CVE-2026-40564

CVE-2026-40564 is a medium-severity vulnerability in Apache Flink Kubernetes Operator with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-552.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 0% (39th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-31846
Weakness: CWE-552
Affected product: Apache Flink Kubernetes Operator
Published: 2026-05-26
Last modified: 2026-06-17

Description

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 addresses. This lets a user with CR create permissions read files from the operator pod's filesystem and pull content from any backing store reachable through Flink's pluggable filesystem layer and access them through the submitted Flink job. Furthermore for fetching from http/https addresses there is currently no allowlist on the URI scheme, no host check, no IP-range restriction, and no protection against pointing the URI at internal or link-local addresses.This issue affects Apache Flink Kubernetes Operator: from 1.3.0 before 1.15.0. Users are recommended to upgrade to version 1.15.0, which fixes the issue.

Frequently asked questions

What is 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 addresses. This lets a user with CR create permissions read files from the operator pod's filesystem and pull content from any backing store reachable through Flink's pluggable filesystem layer and access them through the submitted Flink job. Furthermore for fetching from http/https addresses there is currently no allowlist on the URI scheme, no host check, no IP-range restriction, and no protection against pointing the URI at internal or link-local addresses.This issue affects Apache Flink Kubernetes Operator: from 1.3.0 before 1.15.0. Users are recommended to upgrade to version 1.15.0, which fixes the issue.
How severe is CVE-2026-40564?: CVE-2026-40564 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-40564 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-40564?: CVE-2026-40564 affects Apache Flink Kubernetes Operator. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-40564?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-40564 have an EU (EUVD) identifier?: Yes. CVE-2026-40564 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31846.
When was CVE-2026-40564 published?: CVE-2026-40564 was published on 2026-05-26 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:apache:flink_kubernetes_operator:*:*:*:*:*:*:*:*

Other CWE-552 (Files or Directories Accessible to External Parties) vulnerabilities

CVE-2025-41240 — Critical (CVSS 10.0): Three Bitnami Helm charts mount Kubernetes Secrets under a predictable path (/opt/bitnami/*/secrets) that is located…
CVE-2024-56731 — Critical (CVSS 10.0): Gogs is an open source self-hosted Git service. Prior to version 0.13.3, it's still possible to delete files under the…
CVE-2024-6209 — Critical (CVSS 10.0): Unauthorized file access in WEB Server in ABB ASPECT - Enterprise v3.08.01; NEXUS Series v3.08.01 ; MATRIX Series…
CVE-2025-14771 — Critical (CVSS 9.9): Files or directories accessible to external parties vulnerability in ABB T-MAC Plus. This issue affects T-MAC Plus:…
CVE-2024-39931 — Critical (CVSS 9.9): Gogs through 0.13.0 allows deletion of internal files.
CVE-2021-43821 — Critical (CVSS 9.9): Opencast is an Open Source Lecture Capture & Video Management for Education. Opencast before version 9.10 or 10.6…

Browse all CWE-552 (Files or Directories Accessible to External Parties) vulnerabilities →