CVE-2025-71098

MediumCVSS 5.5

Published: 13/01/2026(UTC)Updated: 14/07/2026(UTC)Translated: 16/07/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.11%

2th percentile - higher than 2% of all known CVEs

Summary

A vulnerability was found in the Linux kernel's ip6gre_header() function in the ip6_gre driver. The bug causes a kernel panic (kernel BUG) due to insufficient skb headroom, which can be exploited by an attacker to crash the system.

Risk Assessment

The risk is the possibility of remotely triggering a kernel panic via specially crafted network traffic, leading to a denial of service (DoS) for the entire system.

Recommendation

Immediately update the Linux kernel to a version containing the fix (commit 5a8c09f6d7f0 or later). If an update is not possible, restrict the use of ip6gre interfaces in production environments.

Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: ip6_gre: make ip6gre_header() robust Over the years, syzbot found many ways to crash the kernel in ip6gre_header() [1]. This involves team or bonding drivers ability to dynamically change their dev->needed_headroom and/or dev->hard_header_len In this particular crash mld_newpack() allocated an skb with a too small reserve/headroom, and by the time mld_sendpack() was called, syzbot managed to attach an ip6gre device. [1] skbuff: skb_under_panic: text:ffffffff8a1d69a8 len:136 put:40 head:ffff888059bc7000 data:ffff888059bc6fe8 tail:0x70 end:0x6c0 dev:team0 ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:213 ! <TASK> skb_under_panic net/core/skbuff.c:223 [inline] skb_push+0xc3/0xe0 net/core/skbuff.c:2641 ip6gre_header+0xc8/0x790 net/ipv6/ip6_gre.c:1371 dev_hard_header include/linux/netdevice.h:3436 [inline] neigh_connected_output+0x286/0x460 net/core/neighbour.c:1618 neigh_output include/net/neighbour.h:556 [inline] ip6_finish_output2+0xfb3/0x1480 net/ipv6/ip6_output.c:136 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline] ip6_finish_output+0x234/0x7d0 net/ipv6/ip6_output.c:220 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247 NF_HOOK+0x9e/0x380 include/linux/netfilter.h:318 mld_sendpack+0x8d4/0xe60 net/ipv6/mcast.c:1855 mld_send_cr net/ipv6/mcast.c:2154 [inline] mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693