{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-98023 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-98023 is a high-severity vulnerability in Linux, published on 25 Sep 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-2026-98023 and fix it if it is affected.\n\nWhat it is: CVE-2026-98023 is a high-severity vulnerability in Linux, published on 25 Sep 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-2026-98023 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-2026-98023/ (Markdown: https://insights.sbomify.com/CVE-2026-98023/index.md)","id":"CVE-2026-98023","markdown":"https://insights.sbomify.com/CVE-2026-98023/index.md","name":"CVE-2026-98023","record":{"aliases":["AZL-104193","BELL-CVE-2026-98023","DEBIAN-CVE-2026-98023","GHSA-vcqm-xvp9-x4jq","UBUNTU-CVE-2026-98023"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service","code_execution"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Linux kernel VXLAN","requires_auth":"low_privilege","summary":"A race condition in Linux kernel VXLAN allows list corruption and use-after-free, potentially causing denial of service or code execution.","user_interaction":"not_required","vuln_class":"race_condition"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":7.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/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\nvxlan: reject dynamic fdb entries that reference a nexthop id\n\nThe commit cited in the Fixes tag allowed VXLAN FDB entries to point to\nFDB nexthops so that overlay traffic could be load balanced across\nmultiple VTEPs. Such entries can only be configured from user space,\ncannot be learned and cannot roam. They only make sense with a user space\ncontrol plane such as E-VPN where data plane learning is disabled.\n\nDespite that, the VXLAN driver does not currently prevent such entries\nfrom being configured with the \"dynamic\" flag. The per-nexthop FDB list\nis only protected by the per-device hash lock, which is not sufficient\nwhen two VXLAN devices point to the same FDB nexthop and therefore share\nthe list. Aging runs in softirq context without RTNL, so an entry deleted\nby one device can race with an addition or deletion from the other,\nleading to list corruption:\n\n  list_del corruption. next-\u003eprev should be ffff8881069d9548, but was\n  dead000000000122. (next=ffff8881069d9448)\n  WARNING: CPU: 0 PID: 90 at lib/list_debug.c:65\n  __list_del_entry_valid_or_report+0x1aa/0x210\n  ...\n   vxlan_fdb_destroy+0x5b8/0xad0\n   vxlan_cleanup+0x328/0x450\n   call_timer_fn+0x2a/0x1c0\n   run_timer_softirq+0x18c/0x210\n  BUG: KASAN: slab-use-after-free in vxlan_fdb_destroy\n\nFix this by rejecting the bogus configuration of dynamic FDB entries that\npoint to FDB nexthops, both when created and when an existing entry is\nupdated. As such, the per-nexthop FDB list is only ever mutated under the\nRTNL lock. Add test cases to make sure that this does not regress in the\nfuture.","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":"vxlan: reject dynamic fdb entries that reference a nexthop id","id":"CVE-2026-98023","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"race_condition","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"s390/ism: folio_put() after error","id":"CVE-2026-98024"},"packages":[],"prev":{"headline":"net: cap tx_queue_len at S16_MAX to prevent oversized ring allocations","id":"CVE-2026-98022"},"products":["Linux"],"published":"2026-09-25","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":"2026-10-19","vendors":["Linux"]},"summary":"A race condition in Linux kernel VXLAN allows list corruption and use-after-free, potentially causing denial of service or code execution.","url":"https://insights.sbomify.com/CVE-2026-98023/"}