Linux kernel: memory corruption

Linux kernel

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix OOB read/write from unvalidated DataOffset in coalesce_t2() coalesce_t2() computes data pointers directly from server-supplied DataOffset fields with no validation against buffer bounds: data_area_of_tgt = (char *)&pSMBt->hdr.Protocol +…

Fix it

Linux

On 5.10.xUpgrade to Linux 5.10.273
On 5.15.xUpgrade to Linux 5.15.224
On 6.1.xUpgrade to Linux 6.1.191
On 6.6.xUpgrade to Linux 6.6.160
On 6.12.xUpgrade to Linux 6.12.113
On 6.18.xUpgrade to Linux 6.18.51
On 7.2.xUpgrade to Linux 7.2.4
On 7.3.xUpgrade to Linux 7.3
On 2.6.xNo fixed 2.6.x listed: move to 5.10.273 or later

First seen: 31 Oct 2026
Last update: 31 Oct 2026, 17:17 UTC
Fixed in: 7.3
7.2.4
6.18.51
6.12.113
6.6.160
6.1.191
5.15.224
5.10.273
Identifiers: CVE-2026-89633
CVSS: 9.8
Source: news
On the menu as: Linux kernel

Check this repository for exposure to one security incident from pwned.coffee. Report first, change nothing until I say so.

## Linux kernel: memory corruption
Severity: critical. Patch status: patched.
Affected: Linux kernel
Fixed in: 7.3, 7.2.4, 6.18.51, 6.12.113, 6.6.160, 6.1.191, 5.15.224, 5.10.273
Ids: CVE-2026-89633

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix OOB read/write from unvalidated DataOffset in coalesce_t2() coalesce_t2() computes data pointers directly from server-supplied DataOffset fields with no validation against buffer bounds: data_area_of_tgt = (char *)&pSMBt->hdr.Protocol +…

## Steps
1. This touches infrastructure (linux). Look in terraform, ansible, cloud-init, Dockerfiles and docs for the product and version we run. If it isn't in the repo, say so and list what a human should check on the box.
2. Fix by release line: Linux: 7.3; 7.2.x → 7.2.4; 6.18.x → 6.18.51; 6.12.x → 6.12.113; 6.6.x → 6.6.160; 6.1.x → 6.1.191; 5.15.x → 5.15.224; 5.10.x → 5.10.273; 2.6.x → no fixed 2.6.x listed: move to 5.10.273 or later.

## Fix by release line
| Line | State | Fix | Until then |
|---|---|---|---|
| Linux | fixed | 7.3 | — |
| Linux 7.2.x | fixed | 7.2.4 | — |
| Linux 6.18.x | fixed | 6.18.51 | — |
| Linux 6.12.x | fixed | 6.12.113 | — |
| Linux 6.6.x | fixed | 6.6.160 | — |
| Linux 6.1.x | fixed | 6.1.191 | — |
| Linux 5.15.x | fixed | 5.15.224 | — |
| Linux 5.10.x | fixed | 5.10.273 | — |
| Linux 2.6.x | migrate | move to 5.10.273 | restrict network access to it |

## Report
A table: file, product or package, version in use, affected yes/no, exact fix. Then anything a human has to check outside the repo.

If you have the pwned.coffee MCP server (https://pwned.coffee/mcp), call lookup_cve("CVE-2026-89633") for the latest, and check_repo with this repo's lockfiles, Dockerfiles and workflows for a full receipt.
Sources: https://git.kernel.org/stable/c/033bc80019f07d158630df4e69b19a49010f54f1 https://nvd.nist.gov/vuln/detail/CVE-2026-89633
https://pwned.coffee/i/in-the-linux-kernel-the-following-vulnerability-has-been-cve-2026-89633

Timeline

31 Oct 2026, 17:17 UTC
Fix status: unknown → patched.
31 Oct 2026
First reported.

Receipt

Exploitation: No known exploitation
Fix by release line: Product Affected Fixed in Source
Linux before 7.3 7.3 CVE record (CNA) checked 31 Oct
Linux 7.2 to before 7.2.4 7.2.4 CVE record (CNA) checked 31 Oct
Linux 6.18 to before 6.18.51 6.18.51 CVE record (CNA) checked 31 Oct
Linux 6.12 to before 6.12.113 6.12.113 CVE record (CNA) checked 31 Oct
Linux 6.6 to before 6.6.160 6.6.160 CVE record (CNA) checked 31 Oct
Linux 6.1 to before 6.1.191 6.1.191 CVE record (CNA) checked 31 Oct
Linux 5.15 to before 5.15.224 5.15.224 CVE record (CNA) checked 31 Oct
Linux 5.10 to before 5.10.273 5.10.273 CVE record (CNA) checked 31 Oct
Linux = 2.6.12 no fixed 2.6.x listed: move to 5.10.273 or later CVE record (CNA) checked 31 Oct
Score: CVSS 9.8 (critical). CVSS 3.1 9.8 (CNA Linux) for CVE-2026-89633
Last checked: 31 Oct 2026, 17:17 UTC

Product	Affected	Fixed in	Source
Linux	before 7.3	7.3	CVE record (CNA) checked 31 Oct
Linux	7.2 to before 7.2.4	7.2.4	CVE record (CNA) checked 31 Oct
Linux	6.18 to before 6.18.51	6.18.51	CVE record (CNA) checked 31 Oct
Linux	6.12 to before 6.12.113	6.12.113	CVE record (CNA) checked 31 Oct
Linux	6.6 to before 6.6.160	6.6.160	CVE record (CNA) checked 31 Oct
Linux	6.1 to before 6.1.191	6.1.191	CVE record (CNA) checked 31 Oct
Linux	5.15 to before 5.15.224	5.15.224	CVE record (CNA) checked 31 Oct
Linux	5.10 to before 5.10.273	5.10.273	CVE record (CNA) checked 31 Oct
Linux	= 2.6.12	no fixed 2.6.x listed: move to 5.10.273 or later	CVE record (CNA) checked 31 Oct

Sources: KEV – CVE record ✓ Vendor ✓

Sources

Wrong fix version, or a source we missed? Send it back to chef@pwned.coffee with the source, and we'll correct it here.

Totalone very hot coffee