CVE-2026-52791 Details
Description
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.
A vulnerability exists in fuse-overlayfs versions prior to 1.17, specifically in the release-1.x C branch. This issue allows a low-privileged process to preserve SUID and SGID mode bits on upper-layer files after truncating a lower-layer file through the merged mount. As a result, the upper-layer file can retain a mode of 4777, which is indicative of SUID being set. The vulnerability arises because the open(O_TRUNC) and truncate operations do not clear these privilege bits, contrary to the ordinary write path which does.
Users can upgrade to fuse-overlayfs version 1.17 or later, where this vulnerability has been addressed.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No CVSS 3.x data is available for this CVE.
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jul 29, 2026References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-266 | Incorrect Privilege Assignment | [email protected] |
Affected Products
No affected product data is available for this CVE.
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 29, 2026 | CVE Modified | CISA-ADP |
| Jul 29, 2026 | New CVE Received | [email protected] |