{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-80612 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-80612 is a critical memory corruption vulnerability in Linux, published on 28 Aug 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-2026-80612 and fix it if it is affected.\n\nWhat it is: CVE-2026-80612 is a critical memory corruption vulnerability in Linux, published on 28 Aug 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-2026-80612 in the wild and no public exploit code.\n\nAffected product: Linux. 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-2026-80612/ (Markdown: https://insights.sbomify.com/CVE-2026-80612/index.md)","id":"CVE-2026-80612","markdown":"https://insights.sbomify.com/CVE-2026-80612/index.md","name":"CVE-2026-80612","record":{"aliases":["DEBIAN-CVE-2026-80612","GHSA-gcxj-phfp-fv28","UBUNTU-CVE-2026-80612"],"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 Linux kernel networking bug causes memory corruption and kernel warnings when forwarding packets with XDP metadata through LWT encapsulation.","user_interaction":"not_required","vuln_class":"memory_corruption"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":9.8,"severity":"critical","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: lwtunnel: Drop skb metadata before LWT encapsulation\n\nskb metadata is meant for passing information between XDP and TC. It lives\nin the skb headroom, immediately before skb-\u003edata. LWT programs cannot\naccess the __sk_buff-\u003edata_meta pseudo-pointer to metadata.\n\nHowever, LWT encapsulation prepends outer headers, moving skb-\u003edata back\nover the headroom where the metadata sits. On an RX-originated (forwarded)\npacket that still carries XDP metadata this goes wrong in two different\nways, depending on the encap type:\n\n1. Non-BPF LWT encaps (mpls, seg6, ioam6 ...) call skb_push()/skb_pull()\n   and silently overwrite the metadata that sits in the headroom.\n\n2) BPF LWT xmit calls bpf_skb_change_head(), which uses skb_data_move().\n   That helper expects metadata immediately before skb-\u003edata. But since\n   the IP output path runs LWT xmit before neighbour output has built\n   the outgoing L2 header, for forwarded packets skb-\u003edata points at the\n   L3 header while skb_mac_header() still points at the old L2 header.\n   skb_data_move() sees metadata ending at skb_mac_header(), not before\n   skb-\u003edata, warns and clears metadata:\n\n  WARNING: CPU: 21 PID: 454557 at include/linux/skbuff.h:4609 skb_data_move+0x47/0x90\n  CPU: 21 UID: 0 PID: 454557 Comm: napi/iconduit-g Tainted: G           O        6.18.21 #1\n  RIP: 0010:skb_data_move+0x47/0x90\n  Call Trace:\n   \u003cIRQ\u003e\n   bpf_skb_change_head+0xe6/0x1a0\n   bpf_prog_...+0x213/0x2e3\n   run_lwt_bpf.isra.0+0x1d3/0x360\n   bpf_xmit+0x46/0xe0\n   lwtunnel_xmit+0xa1/0xf0\n   ip_finish_output2+0x1e7/0x5e0\n   ip_output+0x63/0x100\n   __netif_receive_skb_one_core+0x85/0xa0\n   process_backlog+0x9c/0x150\n   __napi_poll+0x2b/0x190\n   net_rx_action+0x40b/0x7f0\n   handle_softirqs+0xd2/0x270\n   do_softirq+0x3f/0x60\n   \u003c/IRQ\u003e\n\nThat is what happens, as for how to fix it - a received packet that\ncarries metadata can reach an encap through any of the three LWT\nredirect modes:\n\n  LWTUNNEL_STATE_INPUT_REDIRECT\n   ip6_rcv_finish\n     dst_input\n       lwtunnel_input\n\n  LWTUNNEL_STATE_OUTPUT_REDIRECT\n   ip6_rcv_finish\n     dst_input\n       ip6_forward\n         ip6_forward_finish\n           dst_output\n             lwtunnel_output\n\n  LWTUNNEL_STATE_XMIT_REDIRECT\n   ip6_rcv_finish\n     dst_input\n       ip6_forward\n         ip6_forward_finish\n           dst_output\n             ip6_output\n               ip6_finish_output\n                 ip6_finish_output2\n                   lwtunnel_xmit\n\nEvery encap funnels through the three LWT dispatch helpers, so drop the\nmetadata there, right before handing the skb to the encap op. This\nsingle chokepoint covers all encap types and all three redirect modes:\n\n  - lwtunnel_input():  seg6, rpl, ila, seg6_local\n  - lwtunnel_output(): ioam6\n  - lwtunnel_xmit():   mpls, LWT BPF xmit\n\nAlternatively, we could clear the metadata right after TC ingress hook.\nThat would require a compromise, however. Metadata would become\ninaccessible from TC egress (in setups where it actually reaches the\nhook it tact, that is without any L2 tunnels on path).","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: lwtunnel: Drop skb metadata before LWT encapsulation","id":"CVE-2026-80612","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"memory_corruption","year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"veth: fix NAPI leak in XDP enable error path","id":"CVE-2026-80613"},"packages":[],"prev":{"headline":"ACPI: processor_idle: Mark LPI enter functions as __cpuidle","id":"CVE-2026-80611"},"products":["Linux"],"published":"2026-08-28","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-08-29","vendors":["Linux"]},"summary":"A Linux kernel networking bug causes memory corruption and kernel warnings when forwarding packets with XDP metadata through LWT encapsulation.","url":"https://insights.sbomify.com/CVE-2026-80612/"}