# CVE-2026-93286: net: appletalk: fix NULL pointer dereference in aarp_send_ddp()

CVE-2026-93286 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-93286, released September 24, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-93286
- Priority: Routine
- CVSS: 5.5 (Moderate)
- EPSS: 0.0017
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 24, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-93286

## Description

In the Linux kernel, the following vulnerability has been resolved:  net: appletalk: fix NULL pointer dereference in aarp_send_ddp()  aarp_send_ddp() calls atalk_find_dev_addr(dev) in the LocalTalk fast path without checking for NULL. When the device has no AppleTalk interface configured (dev->atalk_ptr == NULL), this leads to a NULL pointer dereference at the at->s_net access.   KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]  RIP: 0010:aarp_send_ddp (net/appletalk/aarp.c:552 (discriminator 2))  Call Trace:   <TASK>   atalk_sendmsg (net/appletalk/ddp.c:1715)   __sys_sendto (net/socket.c:2265 (discriminator 1))   __x64_sys_sendto (net/socket.c:2272)   do_syscall_64 (arch/x86/entry/syscall_64.c:94)   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)  Add a NULL check consistent with the other callers of atalk_find_dev_addr().

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.190-1 | [DEBIAN-CVE-2026-93286](https://patchblox.com/security/data/fix/linux/debian-cve-2026-93286.md) | Sep 24, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.111-1 | [DEBIAN-CVE-2026-93286](https://patchblox.com/security/data/fix/linux/debian-cve-2026-93286.md) | Sep 24, 2026 |
| Linux | linux Debian 14 | 7.1.3-1 | [DEBIAN-CVE-2026-93286](https://patchblox.com/security/data/fix/linux/debian-cve-2026-93286.md) | Sep 24, 2026 |
| Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.111-1~deb12u1 | [DEBIAN-CVE-2026-93286](https://patchblox.com/security/data/fix/linux/debian-cve-2026-93286.md) | Sep 24, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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