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CVE-2026-93811

Linux: ksmbd: Fix acl.sd_buf memory leak and invalid sd_size error handling

Linux LinuxOperating systems
Open in ThreatlineRecord JSON
CVSS
NoneNot scored
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.17%Chance of exploitation activity in the next 30 days, higher than 6% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in86c2625fb9863139b359805fc6be1e31edbd3d65Also 6e6329322ad733c5b23555c609353841560b26bc, 5.15.222 and 2 moreCVE List
Published24 Sep 2026Updated 3 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

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

ksmbd: Fix acl.sd_buf memory leak and invalid sd_size error handling

  1. When ndr_decode_v4_ntacl() fails, the code jumped to free_n_data

which only freed n.data, skipping kfree(acl.sd_buf) and leaking the buffer. Zero-initialize struct xattr_ntacl acl, reorder error labels to out_free to release acl.sd_buf on all error paths.

  1. if (acl.sd_size < sizeof(struct smb_ntsd)) is true, original code

returned success without freeing sd_buf and left stale *pntsd. Set rc = -EINVAL before jumping to out_free to return error code and free buffer.

Text from CVE List

Affected versions 19

  • Linuxaffected: cb69d4d6f709f87c94afa28ae64c501576692171 before f46a70a082bdbfecbe074af8a719c26c4deb58c6CVE List
  • Linuxaffected: 8f0541186e9ad1b62accc9519cc2b7a7240272a7 before 86c2625fb9863139b359805fc6be1e31edbd3d65CVE List
  • Linuxaffected: 8f0541186e9ad1b62accc9519cc2b7a7240272a7 before edc17db83085624a2b1bacf6a4521d7f15571737CVE List
  • Linuxaffected: 8f0541186e9ad1b62accc9519cc2b7a7240272a7 before c3836f55e0dab96314774215e12d87f63fa919f2CVE List
  • Linuxaffected: 8f0541186e9ad1b62accc9519cc2b7a7240272a7 before 6e6329322ad733c5b23555c609353841560b26bcCVE List
  • Linuxaffected: 8f0541186e9ad1b62accc9519cc2b7a7240272a7 before d708a36634bb7b6f94d0e76d587d2ec50b2b93b5CVE List
  • Linuxaffected: 6e8f4abf584253cbaa596ea4ad13110cf61cd4c9CVE List
  • Linuxaffected: 8e33102309bd6839b2e2e158f93a7b378cb4655dCVE List
  • Linuxaffected: 5.15.62 before 5.15.222CVE List
  • Linuxaffected: 5.18.18 before 5.19CVE List
  • Linuxaffected: 5.19.2 before 5.20CVE List
  • Linuxaffected: 6.0CVE List
  • Linuxunaffected: all versions before 6.0CVE List
  • Linuxunaffected: 5.15.222 through 5.15.*CVE List
  • Linuxunaffected: 6.1.189 through 6.1.*CVE List
  • Linuxunaffected: 6.6.158 through 6.6.*CVE List
  • Linuxunaffected: 6.12.111 through 6.12.*CVE List
  • Linuxunaffected: 6.18.53 through 6.18.*CVE List
  • Linuxunaffected: 7.2CVE List

References 6