{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2025-71088", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-71088", "idYear": 2025, "status": "PUBLISHED", "publishedAt": "2026-01-13T15:34:50.377Z", "updatedAt": "2026-10-15T01:10:40.597Z", "importedAt": "2026-10-24T01:57:44.935Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "mptcp: fallback earlier on simult connection", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fallback earlier on simult connection\n\nSyzkaller reports a simult-connect race leading to inconsistent fallback\nstatus:\n\n WARNING: CPU: 3 PID: 33 at net/mptcp/subflow.c:1515 subflow_data_ready+0x40b/0x7c0 net/mptcp/subflow.c:1515\n Modules linked in:\n CPU: 3 UID: 0 PID: 33 Comm: ksoftirqd/3 Not tainted syzkaller #0 PREEMPT(full)\n Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014\n RIP: 0010:subflow_data_ready+0x40b/0x7c0 net/mptcp/subflow.c:1515\n Code: 89 ee e8 78 61 3c f6 40 84 ed 75 21 e8 8e 66 3c f6 44 89 fe bf 07 00 00 00 e8 c1 61 3c f6 41 83 ff 07 74 09 e8 76 66 3c f6 90 <0f> 0b 90 e8 6d 66 3c f6 48 89 df e8 e5 ad ff ff 31 ff 89 c5 89 c6\n RSP: 0018:ffffc900006cf338 EFLAGS: 00010246\n RAX: 0000000000000000 RBX: ffff888031acd100 RCX: ffffffff8b7f2abf\n RDX: ffff88801e6ea440 RSI: ffffffff8b7f2aca RDI: 0000000000000005\n RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000007\n R10: 0000000000000004 R11: 0000000000002c10 R12: ffff88802ba69900\n R13: 1ffff920000d9e67 R14: ffff888046f81800 R15: 0000000000000004\n FS: 0000000000000000(0000) GS:ffff8880d69bc000(0000) knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 0000560fc0ca1670 CR3: 0000000032c3a000 CR4: 0000000000352ef0\n Call Trace:\n \n tcp_data_queue+0x13b0/0x4f90 net/ipv4/tcp_input.c:5197\n tcp_rcv_state_process+0xfdf/0x4ec0 net/ipv4/tcp_input.c:6922\n tcp_v6_do_rcv+0x492/0x1740 net/ipv6/tcp_ipv6.c:1672\n tcp_v6_rcv+0x2976/0x41e0 net/ipv6/tcp_ipv6.c:1918\n ip6_protocol_deliver_rcu+0x188/0x1520 net/ipv6/ip6_input.c:438\n ip6_input_finish+0x1e4/0x4b0 net/ipv6/ip6_input.c:489\n NF_HOOK include/linux/netfilter.h:318 [inline]\n NF_HOOK include/linux/netfilter.h:312 [inline]\n ip6_input+0x105/0x2f0 net/ipv6/ip6_input.c:500\n dst_input include/net/dst.h:471 [inline]\n ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline]\n NF_HOOK include/linux/netfilter.h:318 [inline]\n NF_HOOK include/linux/netfilter.h:312 [inline]\n ipv6_rcv+0x264/0x650 net/ipv6/ip6_input.c:311\n __netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:5979\n __netif_receive_skb+0x1d/0x160 net/core/dev.c:6092\n process_backlog+0x442/0x15e0 net/core/dev.c:6444\n __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7494\n napi_poll net/core/dev.c:7557 [inline]\n net_rx_action+0xa9f/0xfe0 net/core/dev.c:7684\n handle_softirqs+0x216/0x8e0 kernel/softirq.c:579\n run_ksoftirqd kernel/softirq.c:968 [inline]\n run_ksoftirqd+0x3a/0x60 kernel/softirq.c:960\n smpboot_thread_fn+0x3f7/0xae0 kernel/smpboot.c:160\n kthread+0x3c2/0x780 kernel/kthread.c:463\n ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n \n\nThe TCP subflow can process the simult-connect syn-ack packet after\ntransitioning to TCP_FIN1 state, bypassing the MPTCP fallback check,\nas the sk_state_change() callback is not invoked for * -> FIN_WAIT1\ntransitions.\n\nThat will move the msk socket to an inconsistent status and the next\nincoming data will hit the reported splat.\n\nClose the race moving the simult-fallback check at the earliest possible\nstage - that is at syn-ack generation time.\n\nAbout the fixes tags: [2] was supposed to also fix this issue introduced\nby [3]. [1] is required as a dependence: it was not explicitly marked as\na fix, but it is one and it has already been backported before [3]. In\nother words, this commit should be backported up to [3], including [2]\nand [1] if that's not already there.", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "01b7822700f2256900089e00390e119e1ad545df", "status": "affected", "versionType": "git", "lessThan": "b5f46a08269265e2f5e87d855287d6d22de0a32b" }, { "version": "1e777f39b4d75e599a3aac8e0f67d739474f198c", "status": "affected", "versionType": "git", "lessThan": "c9bf315228287653522894df9d851e9b43db9516" }, { "version": "1e777f39b4d75e599a3aac8e0f67d739474f198c", "status": "affected", "versionType": "git", "lessThan": "79f80a7a47849ef1b3c25a0bedcc448b9cb551c1" }, { "version": "1e777f39b4d75e599a3aac8e0f67d739474f198c", "status": "affected", "versionType": "git", "lessThan": "25f1ae942c097b7ae4ce5c2b9c6fefb8e3672b86" }, { "version": "1e777f39b4d75e599a3aac8e0f67d739474f198c", "status": "affected", "versionType": "git", "lessThan": "71154bbe49423128c1c8577b6576de1ed6836830" }, { "version": "6.1.110", "status": "affected", "versionType": "semver", "lessThan": "6.1.160" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "6.2", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "6.2" }, { "version": "6.1.160", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.120", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.65", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.4", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "6.19", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }