CVE-2026-68448: linux
Vulnerability summary
CVE-2026-68448 is a low (CVSS 2.0) vulnerability in linux. EPSS estimates a 0.15% chance of exploitation in the next 30 days, higher than 4.2% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 15 · Related 15Timeline
- 12-08-2026PublishedVulnerability first disclosed.
- 21-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: ovl: check access to copy_file_range source with src mounter creds Commit 5dae222a5ff0c ("vfs: allow copy_file_range to copy across devices") allowed filesystems that implement the copy_file_range() f_op to decide if they want to access cross-sb copy from/to the same fs type. The same commit added checks to verify same sb copy for filesystems that implement ->copy_file_range() and do not support cross-sb copy at the time, namely, to ceph, fuse and nfs. The two remaining fs which implement ->copy_file_range(), cifs and overlayfs started to support cross-sb copy from this time. While overlayfs does support cross-sb copy when the two underlying files are on the same base fs, the copy operation on the two real files from two different overalyfs filesystems is performed with the mounter creds of the destination overlayfs and the read permission access hook for the source file was called with the wrong creds. This could cause either deny of access to copy which would otherwise be allowed (e.g. with splice) or allow read access to file which would otherwise be denied. Fix the latter case by explicitly verifying read access to source file with the source overlayfs mounter creds. The former case remains a quirk of cross-sb overlayfs copy, but userspace could fall back to regular copy so no harm done.
CVSS metrics
1 score · 1 source · 1 versionEPSS trend
Probability
0.15%
Chance of exploitation in the next 30 days
Percentile
4%
Versus all other CVEs
30-day change
0.00 pp
From 0.15% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Ubuntu165 products
- linuxAll versions (No fix recorded) | < 7.0.0-38.38
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 7.0.0-1014.14
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Debian1 product
- linuxAll versions (No fix recorded) | < 7.1.6-1
Linux1 product
- linux≥ 5dae222a5ff0c269730393018a5539cc970a4726, < 7e13e5b087375f1aee1e930503d20efa7084c0fa | ≥ 5dae222a5ff0c269730393018a5539cc970a4726, < 46c296aa678828105842eee29a147508d803d926 | ≥ 5dae222a5ff0c269730393018a5539cc970a4726, < 9ec22c8113d8cf72ed7197bb61037dcad09e50d8 | ≥ 5dae222a5ff0c269730393018a5539cc970a4726, < 1f4a107439d2e43db176e34919933e617cb7f2c5 | ≥ 5dae222a5ff0c269730393018a5539cc970a4726, < a1e0eb8f55cfe09bb31a202a388babc411292656 | 5.3
3 vendors · 167 products
