---
title: "CVE-2026-97555: Linux Kernel smb client - Buffer Overflow"
description: "Linux kernel smb client contains a heap overflow caused by insufficient buffer allocation during DACL owner/group SID rewrite in id_mode_to_cifs_acl, letting attackers cause out-of-bounds write, exploit requires crafted DACL with short original SIDs and longer replacement SIDs."
url: https://panop.io/threat-heartbeat/CVE-2026-97555/
---

# CVE-2026-97555 Linux Kernel smb client - Buffer Overflow

Linux kernel smb client contains a heap overflow caused by insufficient buffer allocation during DACL owner/group SID rewrite in id\_mode\_to\_cifs\_acl, letting attackers cause out-of-bounds write, exploit requires crafted DACL with short original SIDs and longer replacement SIDs.

CVSS base score 8.8 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.52% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-97555)

## Details

Type

Buffer Overflow

Impact

Denial Of Service

CVSS vector

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

Published

25 September 2026

Updated

15 October 2026

## Vendor fix

Update to the latest Linux kernel version containing the fix for this heap overflow.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-97555](https://nvd.nist.gov/vuln/detail/CVE-2026-97555)
- [https://git.kernel.org/stable/c/0ee150794c75bcd0be0e24ff3394f433cbae18cc](https://git.kernel.org/stable/c/0ee150794c75bcd0be0e24ff3394f433cbae18cc)
- [https://git.kernel.org/stable/c/2a9aee9ef5622d58d8aafaa3263b3ffe70e2d9dd](https://git.kernel.org/stable/c/2a9aee9ef5622d58d8aafaa3263b3ffe70e2d9dd)
- [https://git.kernel.org/stable/c/7fa84c9ca690643f429ae2709584a47e74b572c9](https://git.kernel.org/stable/c/7fa84c9ca690643f429ae2709584a47e74b572c9)
- [https://git.kernel.org/stable/c/fb736ab4fb8c4fdb8b2f9ccd3a62e03d11549ca1](https://git.kernel.org/stable/c/fb736ab4fb8c4fdb8b2f9ccd3a62e03d11549ca1)
- [https://git.kernel.org/stable/c/d5cea6766ae1868a51c7d17d77d065b4f55c587f](https://git.kernel.org/stable/c/d5cea6766ae1868a51c7d17d77d065b4f55c587f)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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