ip6_gre: make ip6gre_header() robust
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 4 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-119 and the CVSS impact.
Summary
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
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 3.7 and later | 5.10.248, 5.15.198, 6.1.160, 6.6.120, 6.12.64, 6.18.4, 6.19 | Patch available | CNA |
- Linux VendorLinux Affected 3.7 and later Fixed in 5.10.248, 5.15.198, 6.1.160, 6.6.120, 6.12.64, 6.18.4, 6.19 Patch available CNA
CPE configurations NVD · 10
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 3.7.1 to before 5.10.248; 5.11 to before 5.15.198; 5.16 to before 6.1.160; 6.2 to before 6.6.120; 6.7 to before 6.12.64; 6.13 to before 6.18.4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:3.7:-:*:*:*:*:*:* | 3.7 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:* | 6.19 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:* | 6.19 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:* | 6.19 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:* | 6.19 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:* | 6.19 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:* | 6.19 rc6 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc7:*:*:*:*:*:* | 6.19 rc7 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc8:*:*:*:*:*:* | 6.19 rc8 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 3.7.1 to before 5.10.248; 5.11 to before 5.15.198; 5.16 to before 6.1.160; 6.2 to before 6.6.120; 6.7 to before 6.12.64; 6.13 to before 6.18.4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:3.7:-:*:*:*:*:*:* Versions 3.7 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:* Versions 6.19 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:* Versions 6.19 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:* Versions 6.19 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:* Versions 6.19 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:* Versions 6.19 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:* Versions 6.19 rc6 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc7:*:*:*:*:*:* Versions 6.19 rc7 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc8:*:*:*:*:*:* Versions 6.19 rc8 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.248, 5.15.198, 6.1.160, 6.6.120, 6.12.64, 6.18.4, 6.19
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 7 | Affected | No fix yet |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
Not affected: 1 product
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2025-71098
- 2026-10-03 Alias added: GHSA-qfv4-qxw7-g29f
- 2026-10-19 Weakness changed · CISA ADP
References
Patch 7
- https://git.kernel.org/stable/c/17e7386234f740f3e7d5e58a47b5847ea34c3bc2
- https://git.kernel.org/stable/c/41a1a3140aff295dee8063906f70a514548105e8
- https://git.kernel.org/stable/c/adee129db814474f2f81207bd182bf343832a52e
- https://git.kernel.org/stable/c/1717357007db150c2d703f13f5695460e960f26c
- https://git.kernel.org/stable/c/5fe210533e3459197eabfdbf97327dacbdc04d60
- https://git.kernel.org/stable/c/91a2b25be07ce1a7549ceebbe82017551d2eec92
- https://git.kernel.org/stable/c/db5b4e39c4e63700c68a7e65fc4e1f1375273476
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- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2025-71098 · CVE Program
- CVE-2025-71098 · NVD
- FIRST EPSS
- GHSA-qfv4-qxw7-g29f · GitHub Advisory Database · CC BY 4.0
- CVE-2025-71098 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences