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CVE-2026-47766— crun follows rootfs /dev symlink while creating default devices

Quick assessment

Affected
containers crun
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.

Containers crun是Containers组织开源的一款使用C语言编写的OCI(开放容器倡议)容器运行时库。 Containers crun 1.28之前版本存在后置链接漏洞，该漏洞源于默认设备设置打开容器rootfs /dev目录时未使用O_NOFOLLOW，若OCI bundle包含rootfs/dev符号链接且未挂载/dev，crun会跟随符号链接在容器rootfs外部创建默认设备节点和stdio符号链接，并可能替换目标目录中的ptmx文件，导致攻击者可在容器外部创建或修改文件。

CVSS 5.1 · Medium EPSS 0.20% · P8

Affected Version Matrix 1

VendorProduct Version RangeStatus
containers crun < 1.28 affected
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I. Basic Information for CVE-2026-47766

Vulnerability Information
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Vulnerability Title
crun follows rootfs /dev symlink while creating default devices
Source: CVE Program / CVE List V5
Vulnerability Description
crun is an open source OCI Container Runtime fully written in C. Prior to version 1.28, crun's default device setup opens the container rootfs `/dev` directory without `O_NOFOLLOW`. If an OCI bundle contains `rootfs/dev` as a symlink and the bundle configuration does not mount `/dev`, crun follows that symlink and creates the default device nodes and stdio symlinks at the symlink target outside the container rootfs. In a local rootful crun replay, this created fixed device nodes and symlinks outside the rootfs before crun returned failure. A pre-existing file named `ptmx` in the target directory was also replaced by crun's forced `ptmx -> pts/ptmx` symlink. Version 1.28 fixes the issue.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Source: CVE Program / CVE List V5
Vulnerability Type
CWE-61
Source: CVE Program / CVE List V5
Vulnerability Title
Containers crun 后置链接漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Containers crun是Containers组织开源的一款使用C语言编写的OCI(开放容器倡议)容器运行时库。 Containers crun 1.28之前版本存在后置链接漏洞，该漏洞源于默认设备设置打开容器rootfs /dev目录时未使用O_NOFOLLOW，若OCI bundle包含rootfs/dev符号链接且未挂载/dev，crun会跟随符号链接在容器rootfs外部创建默认设备节点和stdio符号链接，并可能替换目标目录中的ptmx文件，导致攻击者可在容器外部创建或修改文件。
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
containers crun < 1.28 -

II. Public POCs for CVE-2026-47766

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III. Intelligence Information for CVE-2026-47766

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Vendor Advisories for CVE-2026-47766 (1)

Vendor Pages for CVE-2026-47766 (1)

IV. Related Vulnerabilities

Same product: crun
Same vendor: containers
Same weakness: CWE-61

V. Comments for CVE-2026-47766

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