EUVD-2026-36071Severity by source
AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
Primary rating from Vendor (GitHub_M).
CVSS VectorNVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
Lifecycle Timeline
4DescriptionNVD
Fission is an open-source, Kubernetes-native serverless framework that simplifies the deployment of functions and applications on Kubernetes. Prior to version 1.25.0, Unarchive in pkg/utils/zip.go joined each archive entry name with the destination directory via filepath.Join and wrote the result without checking whether the resolved path stayed under the destination. A zip entry named ../../tmp/evil therefore landed at /tmp/evil. An attacker who could control a Package.Spec.Source.URL or Deployment.URL archive could induce the fetcher (running as the per-environment pod's fission-fetcher sidecar) to write files anywhere that process could reach: into other tenants' /packages/<ns>/ directories, into mounted secret/config volumes, or into the fetcher's own binary. This issue has been patched in version 1.25.0.
Articles & Coverage 1
AnalysisAI
Path traversal in Fission Kubernetes serverless framework prior to version 1.25.0 allows authenticated tenants to write files outside the intended extraction directory by submitting a crafted package archive. The fetcher sidecar (fission-fetcher) processes attacker-controlled Package.Spec.Source.URL or Deployment.URL archives via Unarchive in pkg/utils/zip.go, where filepath.Join was used without verifying the resolved path stayed under the destination, enabling cross-tenant file overwrite, tampering with mounted secret/config volumes, or overwriting the fetcher binary itself. …
Unlock full vulnerability intelligence
- Risk assessment & exploitation conditions
- Attack chain visualization
- Remediation with exact patch versions
- Threat intelligence from 22 sources
- Personal watchlist & email alerts
Free forever · No credit card required
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Attacker must have authenticated Kubernetes access sufficient to create or update a Fission Package resource (controlling Package.Spec.Source.URL) or a Deployment resource (controlling Deployment.URL) so the fission-fetcher sidecar will retrieve their zip archive - consistent with the CVSS PR:L rating. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 7.7 vector (AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N) accurately captures the real risk: an authenticated low-privilege tenant who can submit a package definition triggers the fetcher across a scope boundary (S:C) to achieve high integrity impact on other tenants and on the fetcher pod itself, with no confidentiality or availability impact directly scored. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | A tenant with permission to create a Fission Package or Deployment crafts a zip archive containing an entry named '../../../packages/victim-ns/fn/handler.py' (or a path overwriting a mounted secret) and hosts it at an HTTP URL referenced from Package.Spec.Source.URL. When Fission's fetcher sidecar pulls and unzips that archive into its per-environment pod, the traversal escapes the intended /packages/<ns>/ subdirectory and overwrites another tenant's function code or the fetcher's own binary, leading to cross-tenant code execution on the next function invocation. … |
| Remediation | Upgrade Fission to vendor-released patch version 1.25.0 or later, which replaces the unsafe filepath.Join extraction with an os.Root-confined extractor that also rejects absolute paths, parent-traversal entries, and symlink entries up front (PR https://github.com/fission/fission/pull/3444). … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
24 hours: Identify all Fission deployments (versions < 1.25.0), document affected instances, and restrict network access to fission-fetcher components to trusted internal networks only; implement immediate role-based access controls to limit which authenticated users can submit package archives. …
Sign in for detailed remediation steps and compensating controls.
Threat intelligence, references, and detailed analysis are available after sign-in.
More from same product – last 7 days
Privilege escalation in Fission (Kubernetes-native serverless framework) prior to version 1.24.0 allows a tenant with Fu
Privilege escalation in Fission prior to version 1.24.0 allows a tenant holding environments.fission.io create/update RB
Privilege escalation in Fission prior to 1.24.0 allows an authenticated user with permission to create or modify Environ
Privilege escalation in Fission (Kubernetes-native serverless framework) prior to version 1.24.0 allows a tenant with En
Cross-namespace access control bypass in Fission (Kubernetes-native serverless framework) prior to 1.24.0 allows an auth
Share
External POC / Exploit Code
Leaving vuln.today