{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-68136 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-68136 is a critical vulnerability in Linux, published on 10 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-2026-68136 and fix it if it is affected.\n\nWhat it is: CVE-2026-68136 is a critical vulnerability in Linux, published on 10 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-2026-68136 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-2026-68136/ (Markdown: https://insights.sbomify.com/CVE-2026-68136/index.md)","id":"CVE-2026-68136","markdown":"https://insights.sbomify.com/CVE-2026-68136/index.md","name":"CVE-2026-68136","record":{"aliases":["AZL-94919","BELL-CVE-2026-68136","DEBIAN-CVE-2026-68136","GHSA-p4gp-483j-wr28","UBUNTU-CVE-2026-68136"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel","requires_auth":"none","summary":"A missing flush check in Linux kernel GRO allows double aggregation, corrupting packet structures and causing a kernel panic via null pointer dereference.","user_interaction":"not_required","vuln_class":"null_dereference"},"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":[{"id":"CWE-476","name":"NULL Pointer Dereference"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: gro: fix double aggregation of flush-marked skbs\n\nCommit 0ab03f353d36 (\"net-gro: Fix GRO flush when receiving a GSO\npacket.\") added a flush check to skb_gro_receive(), but\nskb_gro_receive_list() lacks the same validation.\n\nAs a result, packets marked with NAPI_GRO_CB(skb)-\u003eflush may still be\nre-aggregated.\n\nThis allows already-GRO'd packets with existing frag_list to be\nre-aggregated into a new GRO session, corrupting the frag_list chain\nstructure. When skb_segment() attempts to unpack these malformed packets,\nit encounters invalid state and triggers a kernel panic.\n\nScenario (Tethering/Device forwarding):\n  1. Driver: Generated aggregated packet P1 via LRO with frag_list\n  2. Dev A: Receives aggregated fraglist packet and flush flag set\n  3. Dev A: Re-enters GRO, skb_gro_receive_list() is called\n  4. Missing flush check allows re-aggregation despite flush flag\n  5. Frag_list chain becomes corrupted (loops or dangling refs)\n  6. Dev B: TX path calls skb_segment(), crashes on corrupted frag_list\n\nRoot cause in skb_segment():\n  The check at line ~4891:\n    if (hsize \u003c= 0 \u0026\u0026 i \u003e= nfrags \u0026\u0026 skb_headlen(list_skb) \u0026\u0026\n        (skb_headlen(list_skb) == len || sg)) {\n\n  When frag_list is corrupted by double aggregation, when list_skb is\n  a NULL pointer from skb-\u003enext, skb_headlen(list_skb) dereference\n  NULL/corrupted pointers occurs.\n\nCall Trace:\n skb_headlen(NULL skb)\n skb_segment\n tcp_gso_segment\n tcp4_gso_segment\n inet_gso_segment\n skb_mac_gso_segment\n __skb_gso_segment\n skb_gso_segment\n validate_xmit_skb\n validate_xmit_skb_list\n sch_direct_xmit\n qdisc_restart\n __qdisc_run\n qdisc_run\n net_tx_action\n\nFix: Add NAPI_GRO_CB(skb)-\u003eflush validation to the early-return check in\nskb_gro_receive_list(), matching the defensive programming pattern of\nskb_gro_receive().","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":"2026-10-23","github_poc":1,"max_poc_stars":0,"metasploit":0,"nuclei":0,"refs":[{"date":"2026-10-23T23:22:16Z","kind":"github_poc","ref":"https://github.com/KernelEditor/CVE-2026-68136","stars":0,"title":"PoC for CVE-2026-68136 / GHSA-p4gp-483j-wr28 — Linux kernel net: gro missing flush check in skb_gro_receive_list(): double aggregation of flush-marked skbs corrupts frag_list, NULL deref in skb_segment() -\u003e kernel panic. User-space C model, verified with ASan/UBSan."}],"tier":"poc_unverified"},"has_fix":true,"headline":"net: gro: fix double aggregation of flush-marked skbs","id":"CVE-2026-68136","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"null_dereference","year":"2026"},"n_packages":0,"n_references":7,"next":{"headline":"net/x25: fix use-after-free in x25_kill_by_neigh()","id":"CVE-2026-68137"},"packages":[],"prev":{"headline":"net: hip04: fix RX buffer leak on build_skb failure","id":"CVE-2026-68135"},"products":["Linux"],"published":"2026-08-10","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A missing flush check in Linux kernel GRO allows double aggregation, corrupting packet structures and causing a kernel panic via null pointer dereference.","url":"https://insights.sbomify.com/CVE-2026-68136/"}