CVE-2025-38574: Debian Linux

High severity, CVSS 7.8. EPSS: 0.4% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: pptp: ensure minimal skb length in pptp_xmit() Commit aabc6596ffb3 ("net: ppp: Add bound checking for skb data on ppp_sync_txmung") fixed ppp_sync_txmunge() We need a similar fix in pptp_xmit(), otherwise we might read uninit data as reported by syzbot. BUG: KMSAN: uninit-value in pptp_xmit+0xc34/0x2720 drivers/net/ppp/pptp.c:193 pptp_xmit+0xc34/0x2720 drivers/net/ppp/pptp.c:193 ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2290 [inline] ppp_input+0x1d6/0xe60 drivers/net/ppp/ppp_generic.c:2314 pppoe_rcv_core+0x1e8/0x760 drivers/net/ppp/pppoe.c:379 sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148 __release_sock+0x1d3/0x330 net/core/sock.c:3213 release_sock+0x6b/0x270 net/core/sock.c:3767 pppoe_sendmsg+0x15d/0xcb0 drivers/net/ppp/pppoe.c:904 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x330/0x3d0 net/socket.c:727 ____sys_sendmsg+0x893/0xd80 net/socket.c:2566 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2620 __sys_sendmmsg+0x2d9/0x7c0 net/socket.c:2709

Affected products

• Debian Debian Linux: version 11.0 only
• Linux Linux Kernel: from 2.6.13, before 5.4.297 (fixed in 5.4.297); from 5.5, before 5.10.241 (fixed in 5.10.241); from 5.11, before 5.15.190 (fixed in 5.15.190); from 5.16, before 6.1.148 (fixed in 6.1.148); from 6.2, before 6.6.102 (fixed in 6.6.102); from 6.7, before 6.12.42 (fixed in 6.12.42); …

Published 2025-08-19. Last modified 2026-07-30.