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CVE-2026-50568— Fission: SanitizeFilePath lexical HasPrefix bypass permits sibling-directory escape

Quick assessment

Affected
fission fission
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Fission是Fission开源的一个基于Kubernetes的函数部署框架。 Fission 1.25.0之前版本存在安全漏洞，该漏洞源于SanitizeFilePath函数使用字符串前缀检查而非目录边界检查，导致以安全目录字符串开头的兄弟目录被接受，租户可通过控制fetcher/构建器共享卷下的兄弟目录诱导写入或读取安全目录之外的文件。

CVSS 3.6 · Low EPSS 0.14% · P3

Affected Version Matrix 1

VendorProduct Version RangeStatus
fission fission < 1.25.0 affected
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I. Basic Information for CVE-2026-50568

Vulnerability Information
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Vulnerability Title
Fission: SanitizeFilePath lexical HasPrefix bypass permits sibling-directory escape
Source: CVE Program / CVE List V5
Vulnerability Description
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, SanitizeFilePath in pkg/utils/utils.go validated that a path stayed under a safe directory by calling strings.HasPrefix(path, safedir). This is a lexical check, not a directory boundary check: /packages-extra/evil starts with /packages, so it passed. The function did not enforce a path-separator boundary, so any sibling directory whose name began with the safe-directory string was accepted. Callers included the builder's Clean handler (pkg/builder/builder.go:208) and the fetcher's Fetch / Upload handlers (pkg/fetcher/fetcher.go). A tenant who could pre-create or control a sibling directory under the fetcher / builder's shared volume could induce a write or read outside the intended safe directory. This issue has been patched in version 1.25.0.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
对路径等价的解析不恰当
Source: CVE Program / CVE List V5
Vulnerability Title
Fission 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Fission是Fission开源的一个基于Kubernetes的函数部署框架。 Fission 1.25.0之前版本存在安全漏洞，该漏洞源于SanitizeFilePath函数使用字符串前缀检查而非目录边界检查，导致以安全目录字符串开头的兄弟目录被接受，租户可通过控制fetcher/构建器共享卷下的兄弟目录诱导写入或读取安全目录之外的文件。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
fission fission < 1.25.0 -

II. Public POCs for CVE-2026-50568

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III. Intelligence Information for CVE-2026-50568

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Patches & Fixes for CVE-2026-50568 (1)

Vendor Advisories for CVE-2026-50568 (1)

Same Patch Batch · fission · 2026-06-10 · 17 CVEs total

CVE-2026-50563 9.9 CRITICAL Fission Container Executor Function PodSpec Injection Leading to Node Escape
CVE-2026-50566 9.9 CRITICAL Fission: Environment Runtime.Container and Builder.Container SecurityContext bypass allows
CVE-2026-50545 9.9 CRITICAL Fission Environment CRD PodSpec Injection Leading to Node Escape and Cluster Takeover
CVE-2026-50564 9.9 CRITICAL Fission Environment CRD podspec passthrough enables hostPID/hostNetwork/privileged pods, n
CVE-2026-46614 9.8 CRITICAL Fission router exposes /fission-function/<ns>/<name> on its public listener, allowing invo
CVE-2026-46612 8.8 HIGH Fission StorageSvc /v1/archive endpoint exposes unauthenticated CRUD over all function arc
CVE-2026-49824 8.5 HIGH Fission: Cross-namespace Environment reference via unvalidated EnvironmentRef in Function
CVE-2026-50570 8.5 HIGH Fission: Incomplete capability denylist in Environment/Function PodSpec validation allows
CVE-2026-49823 7.7 HIGH Fission: Cross-namespace Package read via unvalidated PackageRef in Function admission web
CVE-2026-49822 7.7 HIGH Fission: Cross-namespace event leakage via KubernetesWatchTrigger allows persistent tenant
CVE-2026-49821 7.7 HIGH Fission: Cross-namespace Environment reference in Package allows build-time command execut
CVE-2026-50567 7.7 HIGH Fission: Zip Slip in pkg/utils/zip.go:Unarchive allows fetcher to write outside the destin
CVE-2026-50565 4.9 MEDIUM Fission builder pods auto-mount the fission-builder ServiceAccount token in the user-suppl
CVE-2026-50569 4.3 MEDIUM Fission: HTTPTrigger admission omits RelativeURL / Prefix validation; kubectl apply bypass
CVE-2026-46617 Fission runtime pods automount the fission-fetcher service-account token into the user fun
CVE-2026-46618 Fission builder accepts arbitrary buildcmd strings from Environment.spec.builder.command,

IV. Related Vulnerabilities

Same product: fission
Same vendor: fission
Same weakness: CWE-41

V. Comments for CVE-2026-50568

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