{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-43080 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-43080 is a medium-severity vulnerability in Linux kernel, published on 6 May 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-43080 and fix it if it is affected.\n\nWhat it is: CVE-2026-43080 is a medium-severity vulnerability in Linux kernel, published on 6 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-43080 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-43080/ (Markdown: https://insights.sbomify.com/CVE-2026-43080/index.md)","id":"CVE-2026-43080","markdown":"https://insights.sbomify.com/CVE-2026-43080/index.md","name":"CVE-2026-43080","record":{"aliases":["BELL-CVE-2026-43080","DEBIAN-CVE-2026-43080","GHSA-pmcg-f5m4-2gwp","ROOT-OS-DEBIAN-11-CVE-2026-43080","ROOT-OS-DEBIAN-12-CVE-2026-43080","ROOT-OS-UBUNTU-2204-CVE-2026-43080","ROOT-OS-UBUNTU-2404-CVE-2026-43080","UBUNTU-CVE-2026-43080"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel L2TP","requires_auth":"low_privilege","summary":"An integer overflow in the Linux kernel L2TP UDP encapsulation allows sending oversized packets, potentially causing a kernel warning or denial of service.","user_interaction":"not_required","vuln_class":"integer_overflow"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-674","name":"Uncontrolled Recursion"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nl2tp: Drop large packets with UDP encap\n\nsyzbot reported a WARN on my patch series [1]. The actual issue is an\noverflow of 16-bit UDP length field, and it exists in the upstream code.\nMy series added a debug WARN with an overflow check that exposed the\nissue, that's why syzbot tripped on my patches, rather than on upstream\ncode.\n\nsyzbot's repro:\n\nr0 = socket$pppl2tp(0x18, 0x1, 0x1)\nr1 = socket$inet6_udp(0xa, 0x2, 0x0)\nconnect$inet6(r1, \u0026(0x7f00000000c0)={0xa, 0x0, 0x0, @loopback, 0xfffffffc}, 0x1c)\nconnect$pppl2tp(r0, \u0026(0x7f0000000240)=@pppol2tpin6={0x18, 0x1, {0x0, r1, 0x4, 0x0, 0x0, 0x0, {0xa, 0x4e22, 0xffff, @ipv4={'\\x00', '\\xff\\xff', @empty}}}}, 0x32)\nwritev(r0, \u0026(0x7f0000000080)=[{\u0026(0x7f0000000000)=\"ee\", 0x34000}], 0x1)\n\nIt basically sends an oversized (0x34000 bytes) PPPoL2TP packet with UDP\nencapsulation, and l2tp_xmit_core doesn't check for overflows when it\nassigns the UDP length field. The value gets trimmed to 16 bites.\n\nAdd an overflow check that drops oversized packets and avoids sending\npackets with trimmed UDP length to the wire.\n\nsyzbot's stack trace (with my patch applied):\n\nlen \u003e= 65536u\nWARNING: ./include/linux/udp.h:38 at udp_set_len_short include/linux/udp.h:38 [inline], CPU#1: syz.0.17/5957\nWARNING: ./include/linux/udp.h:38 at l2tp_xmit_core net/l2tp/l2tp_core.c:1293 [inline], CPU#1: syz.0.17/5957\nWARNING: ./include/linux/udp.h:38 at l2tp_xmit_skb+0x1204/0x18d0 net/l2tp/l2tp_core.c:1327, CPU#1: syz.0.17/5957\nModules linked in:\nCPU: 1 UID: 0 PID: 5957 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014\nRIP: 0010:udp_set_len_short include/linux/udp.h:38 [inline]\nRIP: 0010:l2tp_xmit_core net/l2tp/l2tp_core.c:1293 [inline]\nRIP: 0010:l2tp_xmit_skb+0x1204/0x18d0 net/l2tp/l2tp_core.c:1327\nCode: 0f 0b 90 e9 21 f9 ff ff e8 e9 05 ec f6 90 0f 0b 90 e9 8d f9 ff ff e8 db 05 ec f6 90 0f 0b 90 e9 cc f9 ff ff e8 cd 05 ec f6 90 \u003c0f\u003e 0b 90 e9 de fa ff ff 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 4f\nRSP: 0018:ffffc90003d67878 EFLAGS: 00010293\nRAX: ffffffff8ad985e3 RBX: ffff8881a6400090 RCX: ffff8881697f0000\nRDX: 0000000000000000 RSI: 0000000000034010 RDI: 000000000000ffff\nRBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004\nR10: dffffc0000000000 R11: fffff520007acf00 R12: ffff8881baf20900\nR13: 0000000000034010 R14: ffff8881a640008e R15: ffff8881760f7000\nFS:  000055557e81f500(0000) GS:ffff8882a9467000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000200000033000 CR3: 00000001612f4000 CR4: 00000000000006f0\nCall Trace:\n \u003cTASK\u003e\n pppol2tp_sendmsg+0x40a/0x5f0 net/l2tp/l2tp_ppp.c:302\n sock_sendmsg_nosec net/socket.c:727 [inline]\n __sock_sendmsg net/socket.c:742 [inline]\n sock_write_iter+0x503/0x550 net/socket.c:1195\n do_iter_readv_writev+0x619/0x8c0 fs/read_write.c:-1\n vfs_writev+0x33c/0x990 fs/read_write.c:1059\n do_writev+0x154/0x2e0 fs/read_write.c:1105\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7f636479c629\nCode: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 \u003c48\u003e 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007ffffd4241c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000014\nRAX: ffffffffffffffda RBX: 00007f6364a15fa0 RCX: 00007f636479c629\nRDX: 0000000000000001 RSI: 0000200000000080 RDI: 0000000000000003\nRBP: 00007f6364832b39 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\nR13: 00007f6364a15fac R14: 00007f6364a15fa0 R15: 00007f6364a15fa0\n \u003c/TASK\u003e\n\n[1]: https://lore.kernel.org/all/20260226201600.222044-1-alice.kernel@fastmail.im/","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"l2tp: Drop large packets with UDP encap","id":"CVE-2026-43080","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"integer_overflow","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"net: ipa: fix GENERIC_CMD register field masks for IPA v5.0+","id":"CVE-2026-43081"},"packages":[],"prev":{"headline":"perf/x86/intel/uncore: Skip discovery table for offline dies","id":"CVE-2026-43079"},"products":["Linux"],"published":"2026-05-06","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-10-15","vendors":["Linux"]},"summary":"An integer overflow in the Linux kernel L2TP UDP encapsulation allows sending oversized packets, potentially causing a kernel warning or denial of service.","url":"https://insights.sbomify.com/CVE-2026-43080/"}