FR
live
Critical CVSS 9.8

CVE-2026-64089

NVD analysis in progress

In the Linux kernel, the following vulnerability has been resolved: batman-adv: tt: fix negative last_changeset_len batadv_piv_tt::last_changeset_len 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_my_tt_response(), last_changeset_len is temporarily widened to s32. The incorrectly negative s16 value propagates into the s32, causing batadv_tt_prepare_tvlv_local_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_my_tt_response().

What this means

Exposure
Exploitable remotely over the network, without authentication and with no action from the victim.
Impact
An attacker can read sensitive data, modify or destroy data and take the service offline.
Likelihood
Its EPSS score stays low: nothing points to imminent exploitation, which is no reason to leave it unpatched.

What to doPatch without waiting for the next scheduled cycle. Start with the instances exposed to the internet.

Read automatically from the CVSS vector, the weakness type (CWE) and the EPSS score. The technical description above remains the one published by NIST.

Published
19 July 2026
CVSS
9.8 (v3.1) CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
0.55% probability of exploitation within 30 days · above 43% of all CVEs
Sources
nvd
References

Type at least two characters.

navigate open esc dismiss