Fission: Incomplete capability denylist in Environment/Function PodSpec validation allows tenant-added CAP_SYS_TIME and cross-tenant node wall-clock corruption

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.5 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:L

EPSS

• CVE-2026-50570: 0.27% estimated exploitation activity in the next 30 days; percentile 19.84 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Fission v1.24.0 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 (SYSADMIN, NETADMIN, SYSPTRACE, SYSMODULE, DACREADSEARCH, DACOVERRIDE). The denylist omitted CAPSYSTIME, among others. As a result, a tenant who could create a Function or Environment CRD could request securityContext.capabilities.add: ["SYSTIME"], pass Fission's admission validation and merge-layer sanitization, and run attacker-controlled code with CAPSYSTIME in the resulting function or runtime container. Demonstrated consequence: cross-tenant node integrity damage via CAPSYSTIME. The Linux real-time clock is not namespaced — time namespaces virtualize only MONOTONIC and BOOTTIME, never REALTIME — so a tenant container holding CAPSYSTIME could call clocksettime(CLOCKREALTIME)…

Published by the source

28 Jul 2026, 20:12 UTC

Last modified by the source

18 Aug 2026, 15:00 UTC

Source last checked

26 Oct 2026, 15:27 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-qf5v-m7p4-95rp

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GO-2026-6129

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-qf5v-m7p4-95rp

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# Patch Next advisory brief: CVE-2026-50570

Advisory: Fission: Incomplete capability denylist in Environment/Function PodSpec validation allows tenant-added CAP_SYS_TIME and cross-tenant node wall-clock corruption
IDs: CVE-2026-50570, GHSA-qf5v-m7p4-95rp
Record: https://patchnext.com/advisories/cve-2026-50570 (revision 3, source checked 26 Oct 2026, 15:27 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/fission/fission 1.25.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/fission/fission: affected <= 1.24.0; fixed in 1.25.0

## Suggested inspection (read-only)
- Go github.com/fission/fission: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/fission/fission.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-qf5v-m7p4-95rp (OSV record GHSA-qf5v-m7p4-95rp lists affected ranges: Go github.com/fission/fission >=0 <1.25.0 (fixed))
- Verified: https://osv.dev/vulnerability/GO-2026-6129 (OSV record GO-2026-6129 lists affected ranges: Go github.com/fission/fission >=0 <1.25.0 (fixed))
- Verified: https://github.com/advisories/GHSA-qf5v-m7p4-95rp (GitHub-reviewed advisory GHSA-qf5v-m7p4-95rp lists affected ranges: Go github.com/fission/fission >=0 <=1.24.0)

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