cbcvebase.
CVE-2026-46124
published 2026-05-28

CVE-2026-46124: In the Linux kernel, the following vulnerability has been resolved: isofs: validate block number from NFS file handle in isofs_export_iget isofs_fh_to_dentry()…

PriorityP343high7.5CVSS 3.1
AVNACLPRNUINSUCHINAN
EPSS
0.43%
34.4th percentile
In the Linux kernel, the following vulnerability has been resolved: isofs: validate block number from NFS file handle in isofs_export_iget isofs_fh_to_dentry() and isofs_fh_to_parent() pass an attacker- controlled block number (ifid->block or ifid->parent_block) from the NFS file handle to isofs_export_iget(), which only rejects block == 0 before calling isofs_iget() and ultimately sb_bread(). A crafted file handle with fh_len sufficient to pass the check added by commit 0405d4b63d08 ("isofs: Prevent the use of too small fid") can still drive the server to read any in-range block on the backing device as if it were an iso_directory_record. That earlier fix was assigned CVE-2025-37780. sb_bread() on an out-of-range block returns NULL cleanly via the EIO path, so there is no memory-safety violation. For in-range reads of adjacent-partition data on the same block device, the unrelated bytes end up in iso_inode_info fields that reach the NFS client as dentry metadata. The deployment surface (isofs exported over NFS from loop-mounted images) is narrow and requires an authenticated NFS peer, but the malformed-file-handle class is reportable as hardening next to the existing CVE-2025-37780 fix. Reject block >= ISOFS_SB(sb)->s_nzones in isofs_export_iget() so the check covers both isofs_fh_to_dentry() and isofs_fh_to_parent() call sites with a single line.

Affected

16 ranges
VendorProductVersion rangeFixed in
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 5.10.237 < 5.10.2585.10.258
linuxlinux_kernel>= 5.15.181 < 5.15.2095.15.209
linuxlinux_kernel>= 5.4.293 < 5.55.5
linuxlinux_kernel>= 6.1.135 < 6.1.1756.1.175
linuxlinux_kernel>= 6.12.25 < 6.12.886.12.88
linuxlinux_kernel>= 6.14.4 < 6.156.15
linuxlinux_kernel>= 6.15.1 < 6.18.306.18.30
linuxlinux_kernel>= 6.19 < 7.0.77.0.7
linuxlinux_kernel>= 6.6.88 < 6.6.1406.6.140

CVSS provenance

nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
vendor_redhat7.1HIGH
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.