CVE-2025-9708 json
Kubernetes C# Client: improper certificate validation in custom CA mode may lead to man-in-the-middle attacks
published last yr. modified last mo. also GHSA-w7r3-mgwf-4mqq , EUVD-2025-29657
- cvss
- 6.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 23%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- nuget KubernetesClient 17.0.14
- Kubernetes Kubernetes CSharp Client 17.0.14
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Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- last yr.
Exploit prediction
0.31% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N |
| GitHub | 3.1 | 6.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| nuget | KubernetesClient | <17.0.14 |
17.0.14 |
Affected products
- Kubernetes Kubernetes CSharp Client
Classification
- Weakness
-
- CWE-295 Improper Certificate Validation
References
-
groups.google.com
/g/kubernetes-security-announce/c/rLopt2Msvbw/m/rK6XeNw2CgAJ
mailing-list, web
-
github.com
/kubernetes/kubernetes/issues/134063
issue-tracking, web
-
openwall.com
/lists/oss-security/2025/09/16/1
web
-
nvd.nist.gov
/vuln/detail/CVE-2025-9708
advisory
-
github.com
/kubernetes-client/csharp
package
Sources
- CVE List CVE-2025-9708
- GitHub Advisory GHSA-w7r3-mgwf-4mqq
- NVD CVE-2025-9708
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.