CVE-2025-39812

sctp: initialize more fields in sctp_v6_from_sk()

MEDIUM
5.5
CVSS Score
Published: September 16, 2025 at 01:00 PM UTC
Updated: October 19, 2026 at 09:10 PM UTC
3 products affected across 3 vendorsLinux KernelDebian LinuxSIMATIC CN 4100

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%

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

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

2.6.12.1 ≤ v < 5.4.2985.11 ≤ v < 5.15.1915.16 ≤ v < 6.1.1505.5 ≤ v < 5.10.2426.13 ≤ v < 6.16.56.2 ≤ v < 6.6.1046.7 ≤ v < 6.12.451da177e4c3f41524e886b7f1b8a0c1fc7321cac22.6.122.6.12 rc22.6.12 rc32.6.12 rc42.6.12 rc56.176.17 rc16.17 rc26.17 rc3
Vendor states this is fixed in 17d6c7747045e9b802c2f5dfaba260d309d831ae (fixed)
Vendor states this is fixed in 1bbc0c02aea1f1c405bd1271466889c25a1fe01b (fixed)
Vendor states this is fixed in 2e8750469242cad8f01f320131fd5a6f540dbb99 (fixed)
Vendor states this is fixed in 45e4b36593edffb7bbee5828ae820bc10a9fa0f3 (fixed)
Vendor states this is fixed in 463aa96fca6209bb205f49f7deea3817d7ddaa3a (fixed)
Vendor states this is fixed in 65b4693d8bab5370cfcb44a275b4d8dcb06e56bf (fixed)
Vendor states this is fixed in 9546934c2054bba1bd605c44e936619159a34027 (fixed)
Vendor states this is fixed in f6c2cc99fc2387ba6499facd6108f6543382792d (fixed)
Vendor states this is fixed in 2.6.12 (unaffected)
Vendor states this is fixed in 5.10.242 (unaffected)
Vendor states this is fixed in 5.15.191 (unaffected)
Vendor states this is fixed in 5.4.298 (unaffected)
Vendor states this is fixed in 6.1.150 (unaffected)
Vendor states this is fixed in 6.12.45 (unaffected)
Vendor states this is fixed in 6.16.5 (unaffected)
Vendor states this is fixed in 6.17 (unaffected)
Vendor states this is fixed in 6.6.104 (unaffected)
v < V5.0
Affected range stops below V5.0, so it looks safe — our inference, not a vendor statement

References (11)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/17d6c7747045e9b802c2f5dfaba260d309d831ae
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/1bbc0c02aea1f1c405bd1271466889c25a1fe01b
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/2e8750469242cad8f01f320131fd5a6f540dbb99
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/45e4b36593edffb7bbee5828ae820bc10a9fa0f3
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/463aa96fca6209bb205f49f7deea3817d7ddaa3a
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/65b4693d8bab5370cfcb44a275b4d8dcb06e56bf
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/9546934c2054bba1bd605c44e936619159a34027
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/f6c2cc99fc2387ba6499facd6108f6543382792d

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-908

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