CVE-2026-31659: Linux Kernel

Critical severity, CVSS 9.8. EPSS: 0.8% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: batman-adv: reject oversized global TT response buffers batadv_tt_prepare_tvlv_global_data() builds the allocation length for a global TT response in 16-bit temporaries. When a remote originator advertises a large enough global TT, the TT payload length plus the VLAN header offset can exceed 65535 and wrap before kmalloc(). The full-table response path still uses the original TT payload length when it fills tt_change, so the wrapped allocation is too small and batadv_tt_prepare_tvlv_global_data() writes past the end of the heap object before the later packet-size check runs. Fix this by rejecting TT responses whose TVLV value length cannot fit in the 16-bit TVLV payload length field.

Affected products

• Linux Linux Kernel: from 3.13.1, before 5.10.253 (fixed in 5.10.253); from 5.11, before 5.15.203 (fixed in 5.15.203); from 5.16, before 6.1.169 (fixed in 6.1.169); from 6.2, before 6.6.135 (fixed in 6.6.135); from 6.7, before 6.12.82 (fixed in 6.12.82); from 6.13, before 6.18.23 (fixed in 6.18.23); …

Published 2026-04-24. Last modified 2026-06-17.