{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-43100 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-43100 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-2026-43100 and fix it if it is affected.\n\nWhat it is: CVE-2026-43100 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-2026-43100 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-2026-43100/ (Markdown: https://insights.sbomify.com/CVE-2026-43100/index.md)","id":"CVE-2026-43100","markdown":"https://insights.sbomify.com/CVE-2026-43100/index.md","name":"CVE-2026-43100","record":{"aliases":["BELL-CVE-2026-43100","DEBIAN-CVE-2026-43100","GHSA-r5qw-5m8q-6774","UBUNTU-CVE-2026-43100"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Linux kernel bridge","requires_auth":"low_privilege","summary":"A local attacker can cause a kernel crash by creating a bridge with specific options when VLAN filtering is disabled, leading to denial of service.","user_interaction":"not_required","vuln_class":"null_dereference"},"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-476","name":"NULL Pointer Dereference"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbridge: guard local VLAN-0 FDB helpers against NULL vlan group\n\nWhen CONFIG_BRIDGE_VLAN_FILTERING is not set, br_vlan_group() and\nnbp_vlan_group() return NULL (br_private.h stub definitions). The\nBR_BOOLOPT_FDB_LOCAL_VLAN_0 toggle code is compiled unconditionally and\nreaches br_fdb_delete_locals_per_vlan_port() and\nbr_fdb_insert_locals_per_vlan_port(), where the NULL vlan group pointer\nis dereferenced via list_for_each_entry(v, \u0026vg-\u003evlan_list, vlist).\n\nThe observed crash is in the delete path, triggered when creating a\nbridge with IFLA_BR_MULTI_BOOLOPT containing BR_BOOLOPT_FDB_LOCAL_VLAN_0\nvia RTM_NEWLINK. The insert helper has the same bug pattern.\n\n  Oops: general protection fault, probably for non-canonical address 0xdffffc0000000056: 0000 [#1] KASAN NOPTI\n  KASAN: null-ptr-deref in range [0x00000000000002b0-0x00000000000002b7]\n  RIP: 0010:br_fdb_delete_locals_per_vlan+0x2b9/0x310\n  Call Trace:\n   br_fdb_toggle_local_vlan_0+0x452/0x4c0\n   br_toggle_fdb_local_vlan_0+0x31/0x80 net/bridge/br.c:276\n   br_boolopt_toggle net/bridge/br.c:313\n   br_boolopt_multi_toggle net/bridge/br.c:364\n   br_changelink net/bridge/br_netlink.c:1542\n   br_dev_newlink net/bridge/br_netlink.c:1575\n\nAdd NULL checks for the vlan group pointer in both helpers, returning\nearly when there are no VLANs to iterate. This matches the existing\npattern used by other bridge FDB functions such as br_fdb_add() and\nbr_fdb_delete().","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":"bridge: guard local VLAN-0 FDB helpers against NULL vlan group","id":"CVE-2026-43100","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"null_dereference","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"ipv6: ioam: fix potential NULL dereferences in __ioam6_fill_trace_data()","id":"CVE-2026-43101"},"packages":[],"prev":{"headline":"ipv4: icmp: fix null-ptr-deref in icmp_build_probe()","id":"CVE-2026-43099"},"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":"2026-05-11","vendors":["Linux"]},"summary":"A local attacker can cause a kernel crash by creating a bridge with specific options when VLAN filtering is disabled, leading to denial of service.","url":"https://insights.sbomify.com/CVE-2026-43100/"}