{"id":"GHSA-gc3j-79f2-7vvw","summary":"Fission: Cross-namespace event leakage via KubernetesWatchTrigger allows persistent tenant surveillance","details":"### Summary\n\nA 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.\n\n### Details\n\nTwo independent flaws compounded:\n\n1. `pkg/kubewatcher/kubewatcher.go::createKubernetesWatch` used `w.Spec.Namespace` (user-controlled) directly as the Watch target without checking it against `w.Namespace` (the KWT's own namespace). `kubewatcher` established the Watch\nusing its cluster-scoped service account and serialized every Pod/Service/Job change event as full JSON over HTTP POST to the attacker's function.\n2. The validating webhook (`pkg/webhook/kuberneteswatchtrigger.go`) registered `verbs=create` only, so `update`/`patch` requests bypassed validation entirely.\n\nA 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.\n\n### Impact\n\nA 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.\n\n### Fix\n\nFixed in [#3379](https://github.com/fission/fission/pull/3379) and released in [v1.24.0](https://github.com/fission/fission/releases/tag/v1.24.0).\n\n- The validating webhook marker is extended to `verbs=create;update`.\n- `Validate` rejects `KubernetesWatchTrigger.spec.namespace != metadata.namespace`.\n- A controller guard in `createKubernetesWatch` rejects cross-namespace targets that bypass admission and coerces an empty `Spec.Namespace` to the trigger's own namespace.\n\n### Behavioural change\n\nKubernetesWatchTriggers 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.","aliases":["CVE-2026-49822","GO-2026-5854"],"modified":"2026-07-07T16:11:31.958174006Z","published":"2026-06-30T18:16:03Z","database_specific":{"nvd_published_at":"2026-06-10T18:17:10Z","cwe_ids":["CWE-284","CWE-862"],"severity":"HIGH","github_reviewed":true,"github_reviewed_at":"2026-06-30T18:16:03Z"},"references":[{"type":"WEB","url":"https://github.com/fission/fission/security/advisories/GHSA-gc3j-79f2-7vvw"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-49822"},{"type":"WEB","url":"https://github.com/fission/fission/pull/3379"},{"type":"WEB","url":"https://github.com/fission/fission/commit/e2b92663499f4dc3a1e2d38178f39c3c65e0134a"},{"type":"PACKAGE","url":"https://github.com/fission/fission"},{"type":"WEB","url":"https://github.com/fission/fission/releases/tag/v1.24.0"}],"affected":[{"package":{"name":"github.com/fission/fission","ecosystem":"Go","purl":"pkg:golang/github.com/fission/fission"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.24.0"}]}],"database_specific":{"last_known_affected_version_range":"\u003c= 1.23.0","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-gc3j-79f2-7vvw/GHSA-gc3j-79f2-7vvw.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N"}]}