How severe is CVE-2021-25740?

CVE-2021-25740 has a CVSS 3.x base score of 3.1, rated low severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2021-25740 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-25740?

CVE-2021-25740 affects Kubernetes. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-25740?

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

When was CVE-2021-25740 published?

CVE-2021-25740 was published on 2021-09-20 and last updated on 2026-06-17.

CVE-2021-25740

CVE-2021-25740 is a low-severity vulnerability in Kubernetes with a CVSS 3.x base score of 3.1. 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-610.

Key facts

Severity: Low (CVSS 3.x base score 3.1)
CVSS v2: 3.5
EPSS exploit prediction: 2% (76th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-610
Affected product: Kubernetes
Published: 2021-09-20
Last modified: 2026-06-17

Description

A security issue was discovered with Kubernetes that could enable users to send network traffic to locations they would otherwise not have access to via a confused deputy attack.

Frequently asked questions

What is CVE-2021-25740?: A security issue was discovered with Kubernetes that could enable users to send network traffic to locations they would otherwise not have access to via a confused deputy attack.
How severe is CVE-2021-25740?: CVE-2021-25740 has a CVSS 3.x base score of 3.1, rated low severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-25740 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-25740?: CVE-2021-25740 affects Kubernetes. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-25740?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-25740 published?: CVE-2021-25740 was published on 2021-09-20 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:kubernetes:kubernetes:-:*:*:*:*:*:*:*

More vulnerabilities in Kubernetes

CVE-2018-1002105 — Critical (CVSS 9.8): In all Kubernetes versions prior to v1.10.11, v1.11.5, and v1.12.3, incorrect handling of error responses to proxied…
CVE-2017-1000056 — Critical (CVSS 9.8): Kubernetes version 1.5.0-1.5.4 is vulnerable to a privilege escalation in the PodSecurityPolicy admission plugin…
CVE-2016-1906 — Critical (CVSS 9.8): Openshift allows remote attackers to gain privileges by updating a build configuration that was created with an allowed…
CVE-2023-3955 — High (CVSS 8.8): A security issue was discovered in Kubernetes where a user that can create pods on Windows nodes may be able to…
CVE-2023-3676 — High (CVSS 8.8): A security issue was discovered in Kubernetes where a user that can create pods on Windows nodes may be able to…
CVE-2021-25741 — High (CVSS 8.8): A security issue was discovered in Kubernetes where a user may be able to create a container with subpath volume mounts…

All CVEs affecting Kubernetes →

Other CWE-610 vulnerabilities

CVE-2022-27593 — Critical (CVSS 10.0): An externally controlled reference to a resource vulnerability has been reported to affect QNAP NAS running Photo…
CVE-2019-7290 — Critical (CVSS 10.0): An access issue was addressed with additional sandbox restrictions. This issue is fixed in Shortcuts 2.1.3 for iOS. A…
CVE-2017-16088 — Critical (CVSS 10.0): The safe-eval module describes itself as a safer version of eval. By accessing the object constructors, un-sanitized…
CVE-2022-39206 — Critical (CVSS 9.9): Onedev is an open source, self-hosted Git Server with CI/CD and Kanban. When using Docker-based job executors, the…
CVE-2026-47643 — Critical (CVSS 9.8): External control of file name or path in Azure Stack Edge allows an unauthorized attacker to execute code over a…
CVE-2022-20239 — Critical (CVSS 9.8): remap_pfn_range' here may map out of size kernel memory (for example, may map the kernel area), and because the…

Browse all CWE-610 vulnerabilities →