CVE-2025-9708
Kubernetes C# Client: improper certificate validation in custom CA mode may lead to man-in-the-middle attacks
- 6.8MediumCVSS base score
- 0.31%Exploitation in 30 daysEPSS · top 76% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
A vulnerability exists in the Kubernetes C# client where the certificate validation logic accepts properly constructed certificates from any Certificate Authority (CA) without properly verifying the trust chain. This flaw allows a malicious actor to present a forged certificate and potentially intercept or manipulate communication with the Kubernetes API server, leading to possible man-in-the-middle attacks and API impersonation.
Timeline
ID reserved
By kubernetes
- 18 days later
· 18 days later
Published
- 49 days later
· 49 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| kubernetesCNA (assigner) | 3.1 | Medium6.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N |
| NVDNVD · Deferred | 3.1 | Medium6.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.31% · top 76% of all CVEs (11 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.8.
Affected products
Kubernetes · Kubernetes CSharp Client
- affected ≤ 17.0.13
- unaffected 17.0.14
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- NuGetKubernetesClientGHSA-w7r3-mgwf-4mqq (opens in a new tab)
What to do
Solution: Deploy the patch version of the Kubernetes C# client as soon as possible. Alternatively, move the CA certificates into the system trust store instead of specifying them in the kubeconfig file. Note: This approach may introduce new risks, as all processes on the system will begin to trust certificates signed by that CA. If you must use an affected version, you can disable custom CA and add the CA to the machine's trusted root.
References
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-29657 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-w7r3-mgwf-4mqq (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-9708)Record last updated .