CVE-2026-49823: Fission: Cross-namespace Package read via unvalidated PackageRef in Function admission we…

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 functi…

7.7CVSS Score

HIGHSeverity

NOCISA KEV

VulnerabilityImpact Type

📋 Vulnerability Details

CVE ID	CVE-2026-49823
Vendor	go
Affected Product	github.com/fission/fission
Vulnerability Type	Vulnerability
CVSS Score	7.7 (HIGH)
Actively Exploited	❌ No known exploitation
Patch Status	See Vendor Advisory →
Reported By	CYBERDUDEBIVASH SENTINEL APEX Intelligence (via github_advisories)

🔬 Technical Analysis

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

🎯 Known Indicators of Compromise

{"type":"domain","value":"functions.fission.io","confidence_score":0.75,"first_seen":"2026-06-30","source_count":1}

📚 Advisory References

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