Linux Kernel up to 6.17.9 mptcp tcp_rcv_state_process comparison

CVSS Meta Temp Score
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CTI Interest Score
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6.8$0-$5k0.00

Summaryinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.17.9. The affected element is the function tcp_rcv_state_process of the component mptcp. Executing a manipulation can lead to comparison. This vulnerability is handled as CVE-2025-68227. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.17.9. This vulnerability affects the function tcp_rcv_state_process of the component mptcp. The manipulation with an unknown input leads to a comparison vulnerability. The CWE definition for the vulnerability is CWE-697. The product compares two entities in a security-relevant context, but the comparison is incorrect, which may lead to resultant weaknesses. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: mptcp: Fix proto fallback detection with BPF The sockmap feature allows bpf syscall from userspace, or based on bpf sockops, replacing the sk_prot of sockets during protocol stack processing with sockmap's custom read/write interfaces. ''' tcp_rcv_state_process() syn_recv_sock()/subflow_syn_recv_sock() tcp_init_transfer(BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB) bpf_skops_established <== sockops bpf_sock_map_update(sk) <== call bpf helper tcp_bpf_update_proto() <== update sk_prot ''' When the server has MPTCP enabled but the client sends a TCP SYN without MPTCP, subflow_syn_recv_sock() performs a fallback on the subflow, replacing the subflow sk's sk_prot with the native sk_prot. ''' subflow_syn_recv_sock() subflow_ulp_fallback() subflow_drop_ctx() mptcp_subflow_ops_undo_override() ''' Then, this subflow can be normally used by sockmap, which replaces the native sk_prot with sockmap's custom sk_prot. The issue occurs when the user executes accept::mptcp_stream_accept::mptcp_fallback_tcp_ops(). Here, it uses sk->sk_prot to compare with the native sk_prot, but this is incorrect when sockmap is used, as we may incorrectly set sk->sk_socket->ops. This fix uses the more generic sk_family for the comparison instead. Additionally, this also prevents a WARNING from occurring: result from ./scripts/decode_stacktrace.sh: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 337 at net/mptcp/protocol.c:68 mptcp_stream_accept \ (net/mptcp/protocol.c:4005) Modules linked in: ... PKRU: 55555554 Call Trace: <TASK> do_accept (net/socket.c:1989) __sys_accept4 (net/socket.c:2028 net/socket.c:2057) __x64_sys_accept (net/socket.c:2067) x64_sys_call (arch/x86/entry/syscall_64.c:41) do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) RIP: 0033:0x7f87ac92b83d ---[ end trace 0000000000000000 ]---

The advisory is available at git.kernel.org. This vulnerability was named CVE-2025-68227 since 12/16/2025. The exploitation appears to be difficult. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 02/21/2026).

The vulnerability scanner Nessus provides a plugin with the ID 278920 (Linux Distros Unpatched Vulnerability : CVE-2025-68227), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.247, 5.15.197, 6.1.159, 6.6.118, 6.12.60 or 6.17.10 eliminates this vulnerability. Applying the patch 92c4092fe012ecdfa5fb05d394f1c1d8f91ad81c/7ee8f015eb47907745e2070184a8ab1e442ac3c4/344974ea1a3ca30e4920687b0091bda4438cebdb/037cc50589643342d69185b663ecf9d26cce91e8/9b1980b6f23fa30bf12add19f37c7458625099eb/1a0d5c74af9b6ba9ffdf1172de5a1a6df5922a00/c77b3b79a92e3345aa1ee296180d1af4e7031f8f is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (278920) and CERT Bund (WID-SEC-2025-2868). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • Open Source Linux Kernel

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.1
VulDB Meta Temp Score: 6.8

VulDB Base Score: 7.1
VulDB Temp Score: 6.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Comparison
CWE: CWE-697
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 278920
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-68227

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.247/5.15.197/6.1.159/6.6.118/6.12.60/6.17.10
Patch: 92c4092fe012ecdfa5fb05d394f1c1d8f91ad81c/7ee8f015eb47907745e2070184a8ab1e442ac3c4/344974ea1a3ca30e4920687b0091bda4438cebdb/037cc50589643342d69185b663ecf9d26cce91e8/9b1980b6f23fa30bf12add19f37c7458625099eb/1a0d5c74af9b6ba9ffdf1172de5a1a6df5922a00/c77b3b79a92e3345aa1ee296180d1af4e7031f8f

Timelineinfo

12/16/2025 Advisory disclosed
12/16/2025 +0 days CVE reserved
12/16/2025 +0 days VulDB entry created
02/21/2026 +67 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-68227 (🔒)
GCVE (CVE): GCVE-0-2025-68227
GCVE (VulDB): GCVE-100-336826
CERT Bund: WID-SEC-2025-2868 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 12/16/2025 16:13
Updated: 02/21/2026 16:36
Changes: 12/16/2025 16:13 (59), 12/17/2025 11:04 (1), 12/17/2025 17:01 (2), 01/20/2026 01:52 (7), 02/03/2026 10:47 (1), 02/21/2026 16:36 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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