CVE-2026-50570 Fission: Incomplete capability denylist in Environment/Function PodSpec validation allows tenant-added CAP_SYS_TIME and cross-tenant node wall-clock corruption
A tenant can bypass capability restrictions to gain CAP_SYS_TIME, allowing them to alter the node's system clock and potentially disrupt other tenants.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-50570?
CVE-2026-50570 is a high-severity vulnerability in fission, published on 10 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Fission is an open-source, Kubernetes-native serverless framework that simplifies the deployment of functions and applications on Kubernetes. Prior to version 1.25.0, Fission added PodSpec safety validation for tenant-facing Environment and Function CRDs (ValidatePodSpecSafety / ValidateContainerSafety admission webhook + sanitizeContainerSecurityContext executor merge layer), but the capability check was implemented as a fixed denylist of six Linux capabilities (SYS_ADMIN, NET_ADMIN, SYS_PTRACE, SYS_MODULE, DAC_READ_SEARCH, DAC_OVERRIDE). The denylist omitted CAP_SYS_TIME, among others. As a result, a tenant who could create a Function or Environment CRD could request securityContext.capabilities.add: ["SYS_TIME"], pass Fission's admission validation and merge-layer sanitization, and run attacker-controlled code with CAP_SYS_TIME in the resulting function or runtime container. This issue has been patched in version 1.25.0.
Which versions are affected by CVE-2026-50570?
3 open source packages ship an affected version, including github.com/fission/fission.
| Package | Affected | Fixed in |
|---|---|---|
github.com/fission/fission Go | All versions | 1.25.0 |
github.com/fission/fission Go | All versions | 1.25.0 |
github.com/fission/fission Go | All versions | 1.25.0 |
How do I fix CVE-2026-50570?
Upgrade github.com/fission/fission to 1.25.0 or later.
Is CVE-2026-50570 being exploited?
There is no known exploitation of CVE-2026-50570 in the wild and no public exploit code.
Sources
Also known as GHSA-qf5v-m7p4-95rp, GO-2026-6129.