Skip to content
Fencer Vulns
medium 5.1

CVE-2026-47766 json

crun follows rootfs /dev symlink while creating default devices

published 2026-08-14 2 mo ago modified 2026-09-18 51 d ago also EUVD-2026-58714

cvss
5.1
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits
0
none known

Summary

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.

Patch / fix

  • crun Debian 14 1.28-1

debian advisories DEBIAN-CVE-2026-47766

  • crun hummingbird 1 1.28-2.hum1
  • crun-krun hummingbird 1 1.28-2.hum1
  • crun-wasm hummingbird 1 1.28-2.hum1

red hat advisories RHSA-2026:54855

  • crun Linux Micro 6.0 1.14-3.1
  • crun Linux Micro 6.1 1.15-slfo.1.1_2.1

suse advisories SUSE-SU-2026:22395-1SUSE-SU-2026:22247-1

  • crun openSUSE Tumbleweed 1.28-1.1

opensuse advisories openSUSE-SU-2026:11030-1

  • crun Alpine 3.24, Alpine 3.23 1.28-r0

alpine advisories ALPINE-CVE-2026-47766

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-47766 updated cvss 8.4

crun: crun: Arbitrary file creation/overwrite via symlink following

  • Red Hat Enterprise Linux 8 crun Red Hat Enterprise Linux 9 crun Red Hat Enterprise Linux 10 crun Red Hat OpenShift Container Platform 4 crun
    affected: workaround, no fix available “Explicitly configure a dedicated "/dev" mount point inside the container bundle specification, or restrict untrusted users from deploying custom, unvetted OCI container bundles on the host.”
  • Red Hat Hardened Images crun 1.28-2.hum1, crun-krun 1.28-2.hum1, crun-wasm 1.28-2.hum1
    fixed: vendor fix “Explicitly configure a dedicated "/dev" mount point inside the container bundle specification, or restrict untrusted users from deploying custom, unvetted OCI container bundles on the host.” RHSA-2026:54855

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 5.1 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
CNA 4.0 5.1 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • containers crun

Classification

Weakness
  • CWE-61 UNIX Symbolic Link (Symlink) Following

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.