CVE-2026-49823 is a high-severity incorrect authorization vulnerability in github.com/fission/fission (go), affecting versions <= 1.23.0. It is fixed in 1.24.0.
Summary A Fission Function spec carries three reference types, Secret, ConfigMap, and Package. The first two were namespace-validated by the admission webhook; PackageRef.Namespace was not. Details A tenant with functions.fission.io/create in their own namespace could set spec.package.packageref.namespace to any other namespace. When the function is invoked, the fetcher sidecar reads the victim Package using the fission-fetcher service account's namespace-wide get packages permission and writes its contents to /userfunc/deployarchive inside the attacker's pool pod, exposing the victim's source code and any embedded credentials. The fission-fetcher SA holds get packages in every configured function namespace (granted by charts/fission-all/templates/_function-access-role.tpl), so the namespace check was the only barrier between the attacker and any in-cluster Fission Package. Impact A function author in one namespace could read the deployment archive, and therefore the source code and embedded secrets, of any Package in any other namespace. Fix Fixed in #3389 and released in v1.24.0. The admission webhook (pkg/webhook/function.go::Validate) rejects Function.spec.package.packageref.namespace != metadata.namespace. An empty namespace remains accepted (controllers default it to the function's namespace). This shipped together with the EnvironmentRef cross-namespace check (GHSA-cvw6-gfvv-953q). Behavioural change Functions that explicitly set spec.package.packageref.namespace to a different namespace are now rejected at admission.
The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions. Typical impact: unauthorized data access or execution of privileged operations.
CVE-2026-49823 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.
go
github.com/fission/fission (<= 1.23.0)github.com/fission/fission → 1.24.0 (go)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.
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Already deployed Kodem? See CVE-2026-49823 in your environment →Upgrade github.com/fission/fission to 1.24.0 or later to resolve this vulnerability.
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CVE-2026-49823 is a high-severity incorrect authorization vulnerability in github.com/fission/fission (go), affecting versions <= 1.23.0. It is fixed in 1.24.0. The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions.
CVE-2026-49823 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.
github.com/fission/fission (go) versions <= 1.23.0 is affected.
Yes. CVE-2026-49823 is fixed in 1.24.0. Upgrade to this version or later.
Whether CVE-2026-49823 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
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.
Upgrade github.com/fission/fission to 1.24.0 or later.