CVE-2025-39812 sctp: initialize more fields in sctp_v6_from_sk()

What is CVE-2025-39812?

CVE-2025-39812 is a medium-severity vulnerability in Debian Debian Linux, published on 16 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

sctp: initialize more fields in sctp_v6_from_sk()

syzbot found that sin6_scope_id was not properly initialized, leading to undefined behavior.

Clear sin6_scope_id and sin6_flowinfo.

BUG: KMSAN: uninit-value in __sctp_v6_cmp_addr+0x887/0x8c0 net/sctp/ipv6.c:649 __sctp_v6_cmp_addr+0x887/0x8c0 net/sctp/ipv6.c:649 sctp_inet6_cmp_addr+0x4f2/0x510 net/sctp/ipv6.c:983 sctp_bind_addr_conflict+0x22a/0x3b0 net/sctp/bind_addr.c:390 sctp_get_port_local+0x21eb/0x2440 net/sctp/socket.c:8452 sctp_get_port net/sctp/socket.c:8523 [inline] sctp_listen_start net/sctp/socket.c:8567 [inline] sctp_inet_listen+0x710/0xfd0 net/sctp/socket.c:8636 __sys_listen_socket net/socket.c:1912 [inline] __sys_listen net/socket.c:1927 [inline] __do_sys_listen net/socket.c:1932 [inline] __se_sys_listen net/socket.c:1930 [inline] __x64_sys_listen+0x343/0x4c0 net/socket.c:1930 x64_sys_call+0x271d/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:51 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Local variable addr.i.i created at: sctp_get_port net/sctp/socket.c:8515 [inline] sctp_listen_start net/sctp/socket.c:8567 [inline] sctp_inet_listen+0x650/0xfd0 net/sctp/socket.c:8636 __sys_listen_socket net/socket.c:1912 [inline] __sys_listen net/socket.c:1927 [inline] __do_sys_listen net/socket.c:1932 [inline] __se_sys_listen net/socket.c:1930 [inline] __x64_sys_listen+0x343/0x4c0 net/socket.c:1930

Weakness: CWE-908

Which versions are affected by CVE-2025-39812?

It affects 2 products.

Products include Debian Debian Linux, Linux kernel.

How do I fix CVE-2025-39812?

Apply the vendor's patch.

Is CVE-2025-39812 being exploited?

There is no known exploitation of CVE-2025-39812 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-67413, AZL-74706, BELL-CVE-2025-39812, DEBIAN-CVE-2025-39812, GHSA-39p8-x6c9-fprr, ROOT-OS-DEBIAN-11-CVE-2025-39812 and 5 more.