{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-45840 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-45840 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 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-2026-45840 and fix it if it is affected.\n\nWhat it is: CVE-2026-45840 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 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-2026-45840 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-2026-45840/ (Markdown: https://insights.sbomify.com/CVE-2026-45840/index.md)","id":"CVE-2026-45840","markdown":"https://insights.sbomify.com/CVE-2026-45840/index.md","name":"CVE-2026-45840","record":{"aliases":["AZL-88709","BELL-CVE-2026-45840","DEBIAN-CVE-2026-45840","GHSA-gcc5-89x5-vqqc","ROOT-OS-DEBIAN-11-CVE-2026-45840","ROOT-OS-DEBIAN-12-CVE-2026-45840","ROOT-OS-DEBIAN-13-CVE-2026-45840","ROOT-OS-UBUNTU-2204-CVE-2026-45840","ROOT-OS-UBUNTU-2404-CVE-2026-45840","UBUNTU-CVE-2026-45840"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A local attacker with CAP_NET_ADMIN can trigger a kernel panic by setting an oversized upcall PID array in Open vSwitch, causing a 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":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":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nopenvswitch: cap upcall PID array size and pre-size vport replies\n\nThe vport netlink reply helpers allocate a fixed-size skb with\nnlmsg_new(NLMSG_DEFAULT_SIZE, ...) but serialize the full upcall PID\narray via ovs_vport_get_upcall_portids().  Since\novs_vport_set_upcall_portids() accepts any non-zero multiple of\nsizeof(u32) with no upper bound, a CAP_NET_ADMIN user can install a PID\narray large enough to overflow the reply buffer, causing nla_put() to\nfail with -EMSGSIZE and hitting BUG_ON(err \u003c 0).  On systems with\nunprivileged user namespaces enabled (e.g., Ubuntu default), this is\nreachable via unshare -Urn since OVS vport mutation operations use\nGENL_UNS_ADMIN_PERM.\n\n kernel BUG at net/openvswitch/datapath.c:2414!\n Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI\n CPU: 1 UID: 0 PID: 65 Comm: poc Not tainted 7.0.0-rc7-00195-geb216e422044 #1\n RIP: 0010:ovs_vport_cmd_set+0x34c/0x400\n Call Trace:\n  \u003cTASK\u003e\n  genl_family_rcv_msg_doit (net/netlink/genetlink.c:1116)\n  genl_rcv_msg (net/netlink/genetlink.c:1194)\n  netlink_rcv_skb (net/netlink/af_netlink.c:2550)\n  genl_rcv (net/netlink/genetlink.c:1219)\n  netlink_unicast (net/netlink/af_netlink.c:1344)\n  netlink_sendmsg (net/netlink/af_netlink.c:1894)\n  __sys_sendto (net/socket.c:2206)\n  __x64_sys_sendto (net/socket.c:2209)\n  do_syscall_64 (arch/x86/entry/syscall_64.c:63)\n  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)\n  \u003c/TASK\u003e\n Kernel panic - not syncing: Fatal exception\n\nReject attempts to set more PIDs than nr_cpu_ids in\novs_vport_set_upcall_portids(), and pre-compute the worst-case reply\nsize in ovs_vport_cmd_msg_size() based on that bound, similar to the\nexisting ovs_dp_cmd_msg_size().  nr_cpu_ids matches the cap already\nused by the per-CPU dispatch configuration on the datapath side\n(ovs_dp_cmd_fill_info() serialises at most nr_cpu_ids PIDs), so the\ntwo sides stay consistent.","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":"openvswitch: cap upcall PID array size and pre-size vport replies","id":"CVE-2026-45840","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":"netfilter: nfnetlink_osf: fix divide-by-zero in OSF_WSS_MODULO","id":"CVE-2026-45841"},"packages":[],"prev":{"headline":"bpf: reject negative CO-RE accessor indices in bpf_core_parse_spec()","id":"CVE-2026-45839"},"products":["Linux"],"published":"2026-05-27","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":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-10-15","vendors":["Linux"]},"summary":"A local attacker with CAP_NET_ADMIN can trigger a kernel panic by setting an oversized upcall PID array in Open vSwitch, causing a denial of service.","url":"https://insights.sbomify.com/CVE-2026-45840/"}