Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

CVE-2026-68121

Gravedad CVSS v3.1:
ALTA
Tipo:
No Disponible / Otro tipo
Fecha de publicación:
10/08/2026
Última modificación:
19/08/2026

Descripción

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> pppoe: reload header pointer after dev_hard_header()<br /> <br /> pppoe_sendmsg() saves a pointer to the PPPoE header before calling<br /> dev_hard_header(). Device header callbacks are allowed to reallocate the<br /> skb head, invalidating pointers into it.<br /> <br /> This can happen when a send is blocked in copy_from_user() while the first<br /> non-Ethernet port is added to an empty team device. The team&amp;#39;s delegated<br /> GRE header callback then expands the skb head. PPPoE subsequently writes<br /> six bytes through the stale pointer into the freed head.<br /> <br /> Reload the PPPoE header through the skb&amp;#39;s network-header offset after<br /> device header creation. pskb_expand_head() updates that offset when it<br /> relocates the head.