CVE-2026-93539
Unauthenticated GitRepo Spec Mutation via Fleet Git Webhook Receiver
Description
A vulnerability was discovered in Fleet's Git webhook receiver (the gitjob webhook service). When a webhook secret is not configured, incoming webhook requests are accepted without verification, and processing a request can change the spec.pollingInterval field of a matching GitRepo resource in any namespace. A caller with network access to the webhook service and no Kubernetes credentials can therefore alter GitRepo configuration outside the namespaces they are authorized for. This only affects SUSE Rancher Fleet 0.16 before 0.16.2, older versions are not affected.
INFO
Published Date :
Sept. 28, 2026, 3:17 p.m.
Last Modified :
Sept. 28, 2026, 5:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 404e59f5-483d-4b8a-8e7a-e67604dd8afb | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Fleet to version 0.16.2 or later.
- Configure a webhook secret for the Git webhook service.
- Ensure GitRepo resources have appropriate RBAC controls.
- Review and restrict network access to the webhook service.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-93539.
| URL | Resource |
|---|---|
| https://github.com/rancher/fleet/security/advisories/GHSA-8vfv-33cg-g75q |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-93539 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-93539
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-93539 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-93539 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 28, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-93539', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-28T14:59:38.674475Z'} -
New CVE Received by [email protected]
Sep. 28, 2026
Action Type Old Value New Value Added Description A vulnerability was discovered in Fleet's Git webhook receiver (the gitjob webhook service). When a webhook secret is not configured, incoming webhook requests are accepted without verification, and processing a request can change the spec.pollingInterval field of a matching GitRepo resource in any namespace. A caller with network access to the webhook service and no Kubernetes credentials can therefore alter GitRepo configuration outside the namespaces they are authorized for. This only affects SUSE Rancher Fleet 0.16 before 0.16.2, older versions are not affected. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L Added CWE CWE-306 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/93xxx/CVE-2026-93539.json">CVE-2026-93539</a> Added Reference https://github.com/rancher/fleet/security/advisories/GHSA-8vfv-33cg-g75q