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Fencer Vulns
medium 5.6

CVE-2026-88265 json

Crun: crun: /dev/null symlink follow during stdio reopen allows host bind-mount write and chown

published 2026-09-10 1 mo ago modified 2026-11-06 3 d ago also EUVD-2026-75360

cvss
5.6
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 1%
public exploits
0
none known

Summary

A flaw was found in crun. After pivot_root, reopening /dev/null for stdio can follow a symlink and attach a host file to container stdio, then change that file's ownership. Affected versions are crun 1.29.1 and earlier. Default configurations that mount a fresh /dev are not exposed. No fixed release is available yet.

Patch / fix

  • Red Hat Red Hat Hardened Images 1.30-1.hum1
  • crun hummingbird 1 1.30-1.hum1
  • crun-krun hummingbird 1 1.30-1.hum1
  • crun-wasm hummingbird 1 1.30-1.hum1

red hat advisories RHSA-2026:71668

  • crun openSUSE Tumbleweed 1.30.1-1.1

opensuse advisories openSUSE-SU-2026:12162-1

  • crun Alpine 3.24 1.30.1-r0

alpine advisories ALPINE-CVE-2026-88265

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-2026-88265 updated cvss 5.6

crun: crun: /dev/null symlink follow during stdio reopen allows host bind-mount write and chown

  • 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, openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Hardened Images crun 1.30-1.hum1, crun-krun 1.30-1.hum1, crun-wasm 1.30-1.hum1
    fixed: vendor fix RHSA-2026:71668

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
59 d ago

Exploit prediction

0.12% chance of exploitation in the next 30 days, higher than 1% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.6 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:H/A:N

Affected products

  • Red Hat Red Hat Hardened Images
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat OpenShift Container Platform 4
  • Red Hat Red Hat OpenShift Container Platform 5

Classification

Weakness
  • CWE-59 Improper Link Resolution Before File Access

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.