# CVE-2026-50570: Fission incomplete capability denylist in Environment and Function CRDs

Source: https://junglewise.ai/threats/cve-2026-50570-fission-incomplete-capability-denylist-in-environment-and  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-10. Updated: 2026-07-28  
License: CC BY 4.0 with a link back

CVE-2026-50570 · Severity: high · CVSS 8.5 · Published 2026-06-10

Fission is an open-source framework for serverless functions on Kubernetes. A security flaw in how it validates container settings allows a malicious user to gain unauthorized control over the system clock of the underlying server. This can disrupt critical security services, invalidate digital certificates, and cause widespread operational failures for all other users sharing the same server infrastructure.

Technologies: [Fission](https://junglewise.ai/threats/technologies/fission), [github.com/fission/fission (Go)](https://junglewise.ai/threats/technologies/github-com-fission-fission). Vendors: [Fission](https://junglewise.ai/threats/vendors/fission), [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-50570 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-50570 being exploited in the wild.

**How severe is CVE-2026-50570?** High severity, with a CVSS score of 8.5, published 10 June 2026.

**Which products and versions are affected?** Fission <= 1.24.0; github.com/fission/fission (Go) <= 1.24.0, SEMVER:introduced=0,fixed=1.25.0.

**Is there a fix for CVE-2026-50570?** Yes. github.com/fission/fission (Go): upgrade to 1.25.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-50570 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-50570?** Check whether you run Fission or github.com/fission/fission (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/fission/fission (Go): upgrade to 1.25.0 or later

  ```sh
  go get github.com/fission/fission@v1.25.0
  ```


## Technical details

Fission v1.24.0 implemented a security validation layer for Environment and Function Custom Resource Definitions (CRDs) using a fixed denylist of dangerous Linux capabilities. However, the denylist omitted CAP_SYS_TIME, SYS_RAWIO, BPF, and others. An attacker with permissions to create or modify Fission Functions can inject CAP_SYS_TIME into the container's securityContext. Because the Linux real-time clock (CLOCK_REALTIME) is not namespaced, a container with this capability can modify the host node's clock, impacting TLS validation, Kubernetes lease renewals, and token expiration across all tenants on that node. The vulnerability is mitigated if the cluster enforces a 'restricted' Pod Security Admission (PSA) profile. Version 1.25.0 fixes this by replacing the denylist with a strict allowlist.

## Affected products

- fission fission <= 1.24.0

## Identifiers

- CVE-2026-50570
- GHSA-qf5v-m7p4-95rp
- GO-2026-6129

## Timeline

- 2026-06-08: disclosed
- 2026-06-10: advisory: NVD published
- 2026-07-28: patched: GitHub Advisory reviewed and updated with patch details

## References

- [https://api.github.com/users/Yanchon918s](https://api.github.com/users/Yanchon918s)
- [https://github.com/Yanchon918s](https://github.com/Yanchon918s)
- [https://api.github.com/users/Yanchon918s/gists%7B/gist_id%7D](https://api.github.com/users/Yanchon918s/gists%7B/gist_id%7D)
- [https://api.github.com/users/Yanchon918s/repos](https://api.github.com/users/Yanchon918s/repos)
- [https://avatars.githubusercontent.com/u/124195190?v=4](https://avatars.githubusercontent.com/u/124195190?v=4)
- [https://api.github.com/users/Yanchon918s/events%7B/privacy%7D](https://api.github.com/users/Yanchon918s/events%7B/privacy%7D)

## Related threats

- [GO-2026-5849 - Fission: MessageQueueTrigger scaler manager materializes Secret values into Deployment envvars and accepts arbitrary user PodSpec in github.](https://junglewise.ai/threats/go-2026-5849-fission-messagequeuetrigger-scaler-manager-materializes-509f5f41)
- [Fission privilege escalation in MessageQueueTrigger scaler manager](https://junglewise.ai/threats/fission-privilege-escalation-in-messagequeuetrigger-scaler-manager-7fe266a4)
- [Fission HTTPTrigger improper input validation in RelativeURL and Prefix](https://junglewise.ai/threats/cve-2026-50569-fission-httptrigger-improper-input-validation-in-relativeurl-and)
- [Fission path traversal in SanitizeFilePath utility](https://junglewise.ai/threats/cve-2026-50568-fission-path-traversal-in-sanitizefilepath-utility)
- [Fission path traversal in zip extraction utility](https://junglewise.ai/threats/cve-2026-50567-fission-path-traversal-in-zip-extraction-utility)