CVE-2026-63909

high

In the Linux kernel, the following vulnerability has been resolved: ksmbd: OOB read regression in smb_check_perm_dacl() ACE-walk loops Commit d07b26f39246 ("…

Vendor / product: Linux — linux kernel

In the Linux kernel, the following vulnerability has been resolved: ksmbd: OOB read regression in smb_check_perm_dacl() ACE-walk loops Commit d07b26f39246 ("ksmbd: require minimum ACE size in smb_check_perm_dacl()") introduced a transposed bounds check: if (offsetof(struct smb_ace, sid) + aces_size size` (offset 2) even when `aces_size` is 0-3 bytes. This re-opens a 2-byte heap out-of-bounds (OOB) read past the pntsd allocation during subsequent SMB2_CREATE operations. Fix this by properly transposing the comparison to require at least 16 bytes (8-byte offset + 8-byte SID base), matching the correct form used in smb_inherit_dacl().

CVSS

8.1

8.1 (CVSS v3.1)

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

Severity source: NVD CVSS v3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

Timeline (UTC)

Published: 2026-07-19 16:17

Modified: 2026-10-30 14:29

NVD status: Analyzed

Last synced 1 day ago

Verified against the source API 2026-10-30 14:40 UTC

Exploitation

Not listed in CISA KEV (as of last catalog sync)

Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

linux / linux_kernel ≥6.6.140 <6.6.143, ≥6.12.84 <6.12.93, ≥6.18.25 <6.18.35, ≥7.0.2 <7.0.12, 7.1

Weakness classification (CWE)

CWE-125

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

Patch / mitigation: https://git.kernel.org/stable/c/0e60dafe97eca61721f3db456f97d97a80c6c8ae

Patch / mitigation: https://git.kernel.org/stable/c/0fe08c5776a798f46df1fd74b331be26bdd644d6

Patch / mitigation: https://git.kernel.org/stable/c/4f7c131d2bdd7cd64b96f60d10be5ea72253f520

Patch / mitigation: https://git.kernel.org/stable/c/5500ba1d410aed1eded3eb04a76b10cfb4409334

Patch / mitigation: https://git.kernel.org/stable/c/94215d55b09445993929f4fc966061d61de74929

Patch / mitigation: https://git.kernel.org/stable/c/d333af32e4451285e427f2d9c29de3a39f6f6d48

Patch / mitigation: https://git.kernel.org/stable/c/f6324b4240cf0b26a84c33f68a1222d727ff4af2

References

https://git.kernel.org/stable/c/0e60dafe97eca61721f3db456f97d97a80c6c8ae 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/0fe08c5776a798f46df1fd74b331be26bdd644d6 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/4f7c131d2bdd7cd64b96f60d10be5ea72253f520 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/5500ba1d410aed1eded3eb04a76b10cfb4409334 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/94215d55b09445993929f4fc966061d61de74929 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/d333af32e4451285e427f2d9c29de3a39f6f6d48 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/f6324b4240cf0b26a84c33f68a1222d727ff4af2 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Data sources

NVD CVE API 2.0 — fetched 2026-10-30 14:40 UTC · record ↗

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CVE-2026-63909

Affected products

Weakness classification (CWE)

Mitigation & advisories

References

Data sources

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