Description
The netfilter subsystem in the Linux kernel before 4.9 mishandles IPv6 reassembly, which allows local users to cause a denial of service (integer overflow, out-of-bounds write, and GPF) or possibly have unspecified other impact via a crafted application that makes socket, connect, and writev system calls, related to net/ipv6/netfilter/nf_conntrack_reasm.c and net/ipv6/netfilter/nf_defrag_ipv6_hooks.c.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 4.8.15-1 | — |
| Debian 13 | linux | 4.8.15-1 | — |
| Debian 12 | linux | 4.8.15-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-raspi-realtime | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +2 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gke +3 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +2 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe | 4.10.0-32.36~16.04.1 | USN-3361-1 |
Advisories 1
- USN-3361-1 linux-hwe vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
References
- 94626 vdb-entry
- https://github.com/torvalds/linux/commit/9b57da0630c9fd36ed7a20fc0f98dc82cc0777fa
- [oss-security] 20161201 CVE Request: Linux: net: out-of-bounds due do a signedness issue when defragging ipv6 mailing-list
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=9b57da0630c9fd36ed7a20fc0f98dc82cc0777fa
- https://groups.google.com/forum/#%21topic/syzkaller/GFbGpX7nTEo
- https://bugzilla.redhat.com/show_bug.cgi?id=1400904
- [netdev] 20161130 [PATCH 10/11] netfilter: ipv6: nf_defrag: drop mangled skb on ream error mailing-list