Vulnerability in crun (CVE-2026-47766)
Summary
Vulnerability in crun (CVE-2026-47766). Risk of unauthorized operations or information disclosure. Exploitable via O_NOFOLLOW.
Original description
The description as published by the source.
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: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-47766 has been found in crun.
Attackers can target a specific entry point like O_NOFOLLOW over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "crun CVE-2026-47766" on the vendor's site.
CVE-2026-47766 (crun) — CWE-61
Attack surface: O_NOFOLLOW / ptmx
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-61) exists in crun. Attackers reach the vulnerable code path via O_NOFOLLOW.
Check the vendor advisory for the affected versions of crun. Attack surface: O_NOFOLLOW / ptmx.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'crun' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'crun' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
crunを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2026-47766 crun Fixed in: 1.28-r0
- Debian DEBIAN-CVE-2026-47766 crun
- Ubuntu UBUNTU-CVE-2026-47766 crun
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- web github.com