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

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.

Published: 2026-06-10 Last update: 2026-06-10 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-50570 is rated Moderate Risk (40.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.27%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-50570

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.03% 0.27% +0.24%
2 2026-06-11 — 0.03% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-50570

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.1 4.7 [email protected]

Weakness enumeration for CVE-2026-50570

Affected software / configurations for CVE-2026-50570

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-50570

cvelogic Threat Intelligence