fuse-overlayfs release-1.x preserves SUID/SGID bits after truncate/open(O_TRUNC)
Priority MEDIUM 44CWE-266Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- Privilege escalation
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- Partial Red Hat: 1 fixed, 5 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-266.
Summary
fuse-overlayfs is an implementation of overlayfs in FUSE for rootless containers. Prior to 1.17, the release-1.x C branch preserves SUID and SGID mode bits in main.c during open(O_TRUNC) and truncate handling on a copied-up file, allowing a low-privileged process to leave the upper-layer file with mode 4777. This issue is fixed in version 1.17.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00145 3rd percentileScored 2026-11-07
Fix Partial fuse-overlayfs (containers): 1.17Red Hat: 1 advisoryRed Hat: 1 fixed, 5 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| containers | fuse-overlayfs | before 1.17 | 1.17 | Patch available | CNA |
- fuse-overlayfs Vendorcontainers Affected before 1.17 Fixed in 1.17 Patch available CNA
Remediation
- Fix · CNA fuse-overlayfs (containers) Fixed in 1.17
Red Hat 1 advisory
- RHSA-2026:52805 Released 2026-08-10 · Red Hat rating ModerateRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images fuse-overlayfs-1.17-1.hum1@aarch64, fuse-overlayfs-1.17-1.hum1@src, fuse-overlayfs-1.17-1.hum1@x86_64
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
| Red Hat Hardened Images | Fixed | RHSA-2026:52805 |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-52791
- 2026-11-06 Affected versions changed · Red Hat
References
More containers vulnerabilities
- TI-2025-18645 .krun_config.json symlink attack creates or overwrites file on the host in crun CVSS 4.0HIGH 8.5
- TI-2026-23721 Crun incorrectly parses `crun exec` option `-u`, leading to privilege escalation CVSS 3.1HIGH 7.8
- TI-2026-29788 bubblewrap vulnerable to privilege escalation in setuid mode via ptrace CVSS 4.0HIGH 8.7
- TI-2024-07805 Containers/aardvark-dns: tcp query handling flaw in aardvark-dns leading to denial of service CVSS 3.1HIGH 7.5
- TI-2024-08665 Podman: buildah: cri-o: fips crypto-policy directory mounting issue in containers/common go library CVSS 3.1HIGH 8.2
- TI-2020-04347 Privilege escalation in setuid mode via user namespaces in Bubblewrap CVSS 3.1HIGH 7.8
Sources
- CVE-2026-52791 · CVE Program
- CVE-2026-52791 · NVD
- FIRST EPSS
- CVE-2026-52791 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences