PT-2026-61405 · Linux · Linux

CVE-2026-64088 · Published 2026-07-19 · Updated 2026-07-19

NVD

CVSS v3.1

8.8

High

Base vector

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

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

batman-adv: tt: fix negative tt buff len

batadv orig node::tt buff len was declared as s16, but the field is never intended to hold a negative value. When a value greater than 32767 is assigned, it wraps to a negative signed integer.

In batadv send other tt response(), tt buff len is temporarily widened to s32. The incorrectly negative s16 value propagates into the s32, causing batadv tt prepare tvlv global data() to allocate a full sized buffer but populates only a small portion of it with the collected changeset. All remaining bits are kept uninitialized.

Using an u16 avoids this type confusion and ensures that no (negative) sign extension is performed in batadv send other tt response().

Fix

Related Identifiers

CVE-2026-64088

Affected Products

Linux

References · 9

• https://nvd.nist.gov/vuln/detail/CVE-2026-64088 · Security Note
• https://git.kernel.org/stable/c/ed28ead3420c373a7928622f114bc6168075d1e1 · Note
• https://git.kernel.org/stable/c/b64963a2ceeb7529310b6cf253a1e540784422f4 · Note
• https://git.kernel.org/stable/c/3c96dff00998314983b68a3e7caac07a66ebe496 · Note
• https://git.kernel.org/stable/c/730de8733dd90f70d7580a9b329b971f8e1474a2 · Note
• https://git.kernel.org/stable/c/4c4c2f340f4c27373bfcac8dc5032ce7bb474e47 · Note
• https://git.kernel.org/stable/c/32edd2a28e112064020a2f319a8cb8a9e5a09767 · Note
• https://git.kernel.org/stable/c/33e5ede7ce6d92e531920d4bbd6d3e18ef1c6430 · Note
• https://git.kernel.org/stable/c/4dab98961426d0cf6a1599cda6950b7596ca2fcd · Note