CVE-2026-93539
CVE-2026-93539 — Unauthenticated GitRepo Spec Mutation via Fleet Git Webhook Receiver
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.
Published Updated Sources: NVD, SUSE (CNA), GitHub
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Exploit code
public exploit, none observed
EPSS
Not scored
FIRST has not published a score
CVSS base
5.4
medium
Remediation
The vendor's own words where we have them.
Upgrade Rancher to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.
First 24 hours
Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.
- Identify exposed assets running affected vendor/product/version combinations.
- Prioritize based on EPSS, PoC availability, and external exposure.
- Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.
Affected scope
Vendor, product and version as the advisories word them.
| Vendor | Product | Versions | Status |
|---|---|---|---|
| SUSE | Rancher | 0.16.0 to < 0.16.2 | Vulnerable |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Availability
Low
Confidentiality
None
Integrity
Low
Scope
Unchanged
Attack Complexity
Low
Attack Vector
Network
Privileges Req
Low
User Interaction
None
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 5.4 | CVSS 3.1 | medium | 2.8 | 2.5 | suse.de (CNA), SUSE (CNA) |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
Weakness & attack patterns
- CWE-306Missing Authentication for Critical Function
Inferred from the weakness class — not observed against this CVE.
Public exploit
Capability, not use: code existing is a different claim from anyone running it.
Repositories
3
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Prioritize edge telemetry for network-reachable Rancher.
- Monitor for scanner or exploit-pattern traffic after 3 public PoC repositories were reported.
Timeline
What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.
- 2026
Added · CVSS 3.1 5.4 (AV:N)
Sep 28, 2026 · NVD
Initial · CVE published
Sep 28, 2026 · NVD
References
1 on the record
- github.com/rancher/fleet/security/advisories/GHSA-8vfv-33cg-g75q
Exploit, Third Party Advisory
Elsewhere on this site
- SUSEevery CVE for this vendor
- Auth Bypasssame class
- CWE-306other pages naming this weakness
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record1
What should defenders know first?
CVE-2026-93539 is Unauthenticated GitRepo Spec Mutation via Fleet Git Webhook Receiver, a medium vulnerability affecting Rancher from SUSE. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-93539. Public exploit evidence is: 3 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 5.4 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.