Summary
Fission: Cross-namespace event leakage via KubernetesWatchTrigger allows persistent tenant surveillance
A low-privilege developer who could create a KubernetesWatchTrigger (KWT) in their own namespace was able to establish a persistent surveillance channel over any other namespace.
Details
Two independent flaws compounded:
pkg/kubewatcher/kubewatcher.go::createKubernetesWatchusedw.Spec.Namespace(user-controlled) directly as the Watch target without checking it againstw.Namespace(the KWT's own namespace).kubewatcherestablished the Watch
using its cluster-scoped service account and serialized every Pod/Service/Job change event as full JSON over HTTP POST to the attacker's function.- The validating webhook (
pkg/webhook/kuberneteswatchtrigger.go) registeredverbs=createonly, soupdate/patchrequests bypassed validation entirely.
A separate leak: an empty spec.namespace resolved to all namespaces via the controller's default, letting an attacker omit the field to surveil the entire cluster.
Behavioural change
KubernetesWatchTriggers with an unset spec.namespace now watch only their own namespace instead of all namespaces. Anyone relying on the previous all-namespaces behaviour must create a separate KWT per namespace.
Impact
A tenant with kuberneteswatchtriggers.fission.io/create could continuously receive full event payloads for Pods, Services, and Jobs in any namespace, a persistent cross-tenant surveillance channel requiring no additional privileges.
The application does not perform an authorization check before performing a sensitive operation. Typical impact: unauthorized access to restricted functionality or data.
CVE-2026-49822 has a CVSS score of 7.7 (High). 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 (1.24.0); 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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Fixed in #3379 and released in v1.24.0.
- The validating webhook marker is extended to
verbs=create;update. ValidaterejectsKubernetesWatchTrigger.spec.namespace != metadata.namespace.- A controller guard in
createKubernetesWatchrejects cross-namespace targets that bypass admission and coerces an emptySpec.Namespaceto the trigger's own namespace.
Frequently Asked Questions
- What is CVE-2026-49822? CVE-2026-49822 is a high-severity missing authorization vulnerability in github.com/fission/fission (go), affecting versions <= 1.23.0. It is fixed in 1.24.0. The application does not perform an authorization check before performing a sensitive operation.
- How severe is CVE-2026-49822? CVE-2026-49822 has a CVSS score of 7.7 (High). 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-2026-49822? github.com/fission/fission (go) versions <= 1.23.0 is affected.
- Is there a fix for CVE-2026-49822? Yes. CVE-2026-49822 is fixed in 1.24.0. Upgrade to this version or later.
- Is CVE-2026-49822 exploitable, and should I be worried? Whether CVE-2026-49822 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-2026-49822 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-2026-49822? Upgrade
github.com/fission/fissionto 1.24.0 or later.