CVE-2026-46614: Fission router exposes /fission-function/<ns>/<name> on its public listener, allowing invocation of any function without an HTTPTrigger

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 0.7%, percentile 51: FIRST’s model estimates a 0.7% chance of exploitation activity in the next 30 days, higher than 51% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes github.com/fission/fission (Go) <= 1.22.0, fixed in 1.23.0. Check your lockfile, including transitive dependencies.

What it is

Fission is an open-source, Kubernetes-native serverless framework that simplifies the deployment of functions and applications on Kubernetes. Prior to version 1.23.0, the Fission router registers an internal-style route — /fission-function/ and /fission-function/ / — for every Function object, independent of whether any HTTPTrigger exists for that function. The route was mounted on the same listener as user-defined HTTPTriggers (svc/router, port 8888), so any caller who could reach the router could invoke any function by guessing its metadata.name (and namespace), bypassing the host / path / method / method-allow-list restrictions encoded in HTTPTrigger objects. This issue has been patched in version 1.23.0.

From the GitHub advisory

Summary

The Fission router registers an internal-style route — /fission-function/ and /fission-function/ / — for every Function object, independent of whether any HTTPTrigger exists for that function. The route was mounted on the same listener as user-defined HTTPTriggers (svc/router, port 8888), so any caller who could reach the router could invoke any function by guessing its metadata.name (and namespace), bypassing the host / path / method / method-allow-list restrictions encoded in HTTPTrigger objects.

Affected component

- pkg/router/httpTriggers.go:280-284 — internalRoute registration via utils.UrlForFunction(fn.Name, fn.Namespace), bound to the function handler.

Impact

Weakness type: CWE-284, CWE-862.

Product: github.com/fission/fission (Go) · Assigned by: GitHub_M · Published: 2026-06-10

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: none (no login)
• User interaction: none
• Scope: unchanged

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.65% probability of exploitation activity in the next 30 days; percentile 51.

Timeline

• 2026-05-21 — GitHub-reviewed advisory GHSA-3g33-6vg6-27m8 published (critical)
• 2026-06-10 — CVE record published by GitHub_M
• 2026-06-11 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-3g33-6vg6-27m8 github.com
2. CVE.org record CVE-2026-46614 cve.org
3. NVD entry CVE-2026-46614 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com
4. github.com github.com

Critical Go advisories · Today’s Security Digest