CVE-2026-89634

CriticalCVSS 9.1/10Last modified Oct 19, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

smb: client: fix ALIGN() overflow in symlink_data() error context loop

The check added by commit 7d9a7f1f96cd ("smb/client: fix possible infinite loop and oob read in symlink_data()") compared the post-ALIGN length against the remaining buffer, but ALIGN() itself can overflow: for ErrorDataLength near UINT32_MAX (e.g. 0xFFFFFFF9), ALIGN(x, 8) wraps to 0, so the subsequent bounds check passes, and the loop advances by zero bytes leaving 'p' pointing into stale data.

Fix by checking the raw ErrorDataLength against the remaining space before applying ALIGN(), then checking again after. Since raw_len is bounded by the buffer, raw_len + 7 cannot overflow, so the second check is an exact post-alignment bounds guard.

Metrics

CVSS 3.1 9.1/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Affected software

Source: the vendor's advisory (CNA). NVD analysis pending.

No affected versions have been published.

Timeline

Published
Sep 11, 2026
Last modified
Oct 19, 2026
NVD status
Received

Related CVEs from 2026

CVE-2026-896359.8In the Linux kernel, the following vulnerability has been resolved: ksmbd: only rebind the reopened file's own oplock on durable reconnect CVE-2026-896369.8In the Linux kernel, the following vulnerability has been resolved: smb: client: clear ce->tgthint in free_tgts() When free_tgts() frees aCVE-2026-896379.8In the Linux kernel, the following vulnerability has been resolved: smb: client: fix UAF and buffer leak in cifs_check_trans2() for malformCVE-2026-896387.8In the Linux kernel, the following vulnerability has been resolved: smb: client: clear setuid/setgid bit on write with cifsacl/modefromsid/CVE-2026-896397.1In the Linux kernel, the following vulnerability has been resolved: cifs: use cifs_invalidate_cache() in cifs_do_truncate() for O_TRUNC ciCVE-2026-89647.5Spoofing issue in the Popup Blocker component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.CVE-2026-896407.1In the Linux kernel, the following vulnerability has been resolved: cifs: fix loff_t underflow in cifs_remap_file_range() when len == 0 WiCVE-2026-896417.8In the Linux kernel, the following vulnerability has been resolved: cifs: clear tcon after cifsFileInfo_put() in cifs_file_set_size() WhenCVE-2026-89642In the Linux kernel, the following vulnerability has been resolved: cifs: call pagecache_isize_extended() in cifs_setsize() when extending CVE-2026-896439.8In the Linux kernel, the following vulnerability has been resolved: audit: avoid dropping live tree ref on fsnotify rule autoremove audit_CVE-2026-89644In the Linux kernel, the following vulnerability has been resolved: btrfs: fix extent map leak in NOCOW direct I/O write btrfs_dio_iomap_bCVE-2026-89645In the Linux kernel, the following vulnerability has been resolved: btrfs: drop recovered reloc root refs on recovery failure During reloc
CVE-2026-89634: Critical severity, CVSS 9.1 | Vulnix