{"cve":"CVE-2026-68448","nvd":{"published":"2026-08-12T01:17:07.697","modified":"2026-10-21T13:19:31.400","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\novl: check access to copy_file_range source with src mounter creds\n\nCommit 5dae222a5ff0c (\"vfs: allow copy_file_range to copy across devices\")\nallowed filesystems that implement the copy_file_range() f_op to decide\nif they want to access cross-sb copy from/to the same fs type.\n\nThe same commit added checks to verify same sb copy for filesystems that\nimplement ->copy_file_range() and do not support cross-sb copy at the\ntime, namely, to ceph, fuse and nfs.\n\nThe two remaining fs which implement ->copy_file_range(), cifs and\noverlayfs started to support cross-sb copy from this time.\n\nWhile overlayfs does support cross-sb copy when the two underlying files\nare on the same base fs, the copy operation on the two real files from\ntwo different overalyfs filesystems is performed with the mounter\ncreds of the destination overlayfs and the read permission access hook\nfor the source file was called with the wrong creds.\n\nThis could cause either deny of access to copy which would otherwise be\nallowed (e.g. with splice) or allow read access to file which would\notherwise be denied.\n\nFix the latter case by explicitly verifying read access to source file\nwith the source overlayfs mounter creds.\n\nThe former case remains a quirk of cross-sb overlayfs copy, but\nuserspace could fall back to regular copy so no harm done.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/1f4a107439d2e43db176e34919933e617cb7f2c5","https://git.kernel.org/stable/c/46c296aa678828105842eee29a147508d803d926","https://git.kernel.org/stable/c/7e13e5b087375f1aee1e930503d20efa7084c0fa","https://git.kernel.org/stable/c/9ec22c8113d8cf72ed7197bb61037dcad09e50d8","https://git.kernel.org/stable/c/a1e0eb8f55cfe09bb31a202a388babc411292656"],"products":[],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-68448","score":0.00157,"percentile":0.04788,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}