{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-43194 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-43194 is a high-severity denial of service vulnerability in Linux kernel, published on 6 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-43194 and fix it if it is affected.\n\nWhat it is: CVE-2026-43194 is a high-severity denial of service vulnerability in Linux kernel, published on 6 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-43194 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-2026-43194/ (Markdown: https://insights.sbomify.com/CVE-2026-43194/index.md)","id":"CVE-2026-43194","markdown":"https://insights.sbomify.com/CVE-2026-43194/index.md","name":"CVE-2026-43194","record":{"aliases":["BELL-CVE-2026-43194","DEBIAN-CVE-2026-43194","GHSA-6g7r-xrvq-rpc8","ROOT-OS-DEBIAN-11-CVE-2026-43194","ROOT-OS-UBUNTU-2204-CVE-2026-43194","ROOT-OS-UBUNTU-2404-CVE-2026-43194","UBUNTU-CVE-2026-43194"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel networking","requires_auth":"none","summary":"A flaw in Linux kernel TCP handling causes connections to stall indefinitely when GSO frames encounter transmission errors, leading to denial of service.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":7.5,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-754","name":"Improper Check for Unusual or Exceptional Conditions"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: consume xmit errors of GSO frames\n\nudpgro_frglist.sh and udpgro_bench.sh are the flakiest tests\ncurrently in NIPA. They fail in the same exact way, TCP GRO\ntest stalls occasionally and the test gets killed after 10min.\n\nThese tests use veth to simulate GRO. They attach a trivial\n(\"return XDP_PASS;\") XDP program to the veth to force TSO off\nand NAPI on.\n\nDigging into the failure mode we can see that the connection\nis completely stuck after a burst of drops. The sender's snd_nxt\nis at sequence number N [1], but the receiver claims to have\nreceived (rcv_nxt) up to N + 3 * MSS [2]. Last piece of the puzzle\nis that senders rtx queue is not empty (let's say the block in\nthe rtx queue is at sequence number N - 4 * MSS [3]).\n\nIn this state, sender sends a retransmission from the rtx queue\nwith a single segment, and sequence numbers N-4*MSS:N-3*MSS [3].\nReceiver sees it and responds with an ACK all the way up to\nN + 3 * MSS [2]. But sender will reject this ack as TCP_ACK_UNSENT_DATA\nbecause it has no recollection of ever sending data that far out [1].\nAnd we are stuck.\n\nThe root cause is the mess of the xmit return codes. veth returns\nan error when it can't xmit a frame. We end up with a loss event\nlike this:\n\n  -------------------------------------------------\n  |   GSO super frame 1   |   GSO super frame 2   |\n  |-----------------------------------------------|\n  | seg | seg | seg | seg | seg | seg | seg | seg |\n  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  8  |\n  -------------------------------------------------\n     x    ok    ok    \u003cok\u003e|  ok    ok    ok   \u003cx\u003e\n                          \\\\\n\t\t\t   snd_nxt\n\n\"x\" means packet lost by veth, and \"ok\" means it went thru.\nSince veth has TSO disabled in this test it sees individual segments.\nSegment 1 is on the retransmit queue and will be resent.\n\nSo why did the sender not advance snd_nxt even tho it clearly did\nsend up to seg 8? tcp_write_xmit() interprets the return code\nfrom the core to mean that data has not been sent at all. Since\nTCP deals with GSO super frames, not individual segment the crux\nof the problem is that loss of a single segment can be interpreted\nas loss of all. TCP only sees the last return code for the last\nsegment of the GSO frame (in \u003c\u003e brackets in the diagram above).\n\nOf course for the problem to occur we need a setup or a device\nwithout a Qdisc. Otherwise Qdisc layer disconnects the protocol\nlayer from the device errors completely.\n\nWe have multiple ways to fix this.\n\n 1) make veth not return an error when it lost a packet.\n    While this is what I think we did in the past, the issue keeps\n    reappearing and it's annoying to debug. The game of whack\n    a mole is not great.\n\n 2) fix the damn return codes\n    We only talk about NETDEV_TX_OK and NETDEV_TX_BUSY in the\n    documentation, so maybe we should make the return code from\n    ndo_start_xmit() a boolean. I like that the most, but perhaps\n    some ancient, not-really-networking protocol would suffer.\n\n 3) make TCP ignore the errors\n    It is not entirely clear to me what benefit TCP gets from\n    interpreting the result of ip_queue_xmit()? Specifically once\n    the connection is established and we're pushing data - packet\n    loss is just packet loss?\n\n 4) this fix\n    Ignore the rc in the Qdisc-less+GSO case, since it's unreliable.\n    We already always return OK in the TCQ_F_CAN_BYPASS case.\n    In the Qdisc-less case let's be a bit more conservative and only\n    mask the GSO errors. This path is taken by non-IP-\"networks\"\n    like CAN, MCTP etc, so we could regress some ancient thing.\n    This is the simplest, but also maybe the hackiest fix?\n\nSimilar fix has been proposed by Eric in the past but never committed\nbecause original reporter was working with an OOT driver and wasn't\nproviding feedback (see Link).","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":"net: consume xmit errors of GSO frames","id":"CVE-2026-43194","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"drm/amdgpu: validate user queue size constraints","id":"CVE-2026-43195"},"packages":[],"prev":{"headline":"nfsd: fix nfs4_file refcount leak in nfsd_get_dir_deleg()","id":"CVE-2026-43193"},"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":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A flaw in Linux kernel TCP handling causes connections to stall indefinitely when GSO frames encounter transmission errors, leading to denial of service.","url":"https://insights.sbomify.com/CVE-2026-43194/"}