Summary
Fission: HTTPTrigger admission omits RelativeURL / Prefix validation; kubectl apply bypasses CLI checks
HTTPTriggerSpec.Validate() validated Methods, FunctionReference, Host, IngressConfig, and CorsConfig, but silently skipped RelativeURL and Prefix. Those two fields were validated at the CLI level only
(pkg/fission-cli/cmd/httptrigger/create.go:83). The post-CRD-modernization webhook for HTTPTrigger was retired in favor of API-server CEL, and CEL had no rules on those fields either, so an HTTPTrigger created via kubectl apply or
a direct Kubernetes REST API call bypassed every URL-level check.
A tenant with HTTPTrigger create permission could therefore create triggers whose RelativeURL or Prefix:
- was empty (with both fields unset, the trigger has no URL),
- did not start with
/, - was exactly
/(claiming the entire router root), - contained
..traversal segments (e.g./api/../admin), - collided with router-owned routes:
/router-healthz,/readyz,/_version,/auth/login, - collided with the router-internal function prefix
/fission-function/<ns>/<name>.
Affected
- Project:
github.com/fission/fission - Versions: all versions through v1.24.0
- Audited commit:
647c141 - Component:
pkg/apis/core/v1/validation.go:HTTPTriggerSpec.Validate(and the missing CEL onHTTPTriggerSpec) - Configuration: default
Fix section (paste into the Fix / Patches field)
Fixed in v1.25.0 by:
- PR #3464 (commit
0deed6bf), enforce the path-safety invariants at both admission layers so the API
server's CEL evaluation and the Go-sideHTTPTriggerSpec.Validate()agree:- Three
+kubebuilder:validation:XValidationrules onHTTPTriggerSpec(the API server's CEL admission gate, regenerated intocrds/v1/fission.io_httptriggers.yaml):- at least one of
relativeurlorprefixmust be non-empty; relativeurl, when set, must start with/, must not be/, must contain no..segment, must not be in the reserved exact-path set, and must not start with/fission-function/;prefix, when set, the same rules guarded byhas(self.prefix).
- at least one of
validateTriggerPathhelper inpkg/apis/core/v1/validation.go, invoked fromHTTPTriggerSpec.Validate(), mirrors the CEL rules so the CLI's early rejection and the router reconciler's status-Condition path match what the API
server admits.
- Three
Regression coverage: a new TestHTTPTriggerSpecValidate_Path table in pkg/apis/core/v1/validation_validators_test.go exercises every PoC case from the advisory plus literal ..-prefixed-segment positives that must remain allowed.
Impact
The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths. Typical impact: varies by context: data corruption, logic bypass, or denial of service.
CVE-2026-50569 has a CVSS score of 4.3 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.25.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-50569? CVE-2026-50569 is a medium-severity improper input validation vulnerability in github.com/fission/fission (go), affecting versions <= 1.24.0. It is fixed in 1.25.0. The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths.
- How severe is CVE-2026-50569? CVE-2026-50569 has a CVSS score of 4.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/fission/fission are affected by CVE-2026-50569? github.com/fission/fission (go) versions <= 1.24.0 is affected.
- Is there a fix for CVE-2026-50569? Yes. CVE-2026-50569 is fixed in 1.25.0. Upgrade to this version or later.
- Is CVE-2026-50569 exploitable, and should I be worried? Whether CVE-2026-50569 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-50569 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-50569? Upgrade
github.com/fission/fissionto 1.25.0 or later.