{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-21959 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-21959 is a high-severity vulnerability in Linux kernel, published on 1 Apr 2025. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2025-21959 and fix it if it is affected.\n\nWhat it is: CVE-2025-21959 is a high-severity vulnerability in Linux kernel, published on 1 Apr 2025. 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-2025-21959 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-2025-21959/ (Markdown: https://insights.sbomify.com/CVE-2025-21959/index.md)","id":"CVE-2025-21959","markdown":"https://insights.sbomify.com/CVE-2025-21959/index.md","name":"CVE-2025-21959","record":{"aliases":["AZL-60273","AZL-60297","BELL-CVE-2025-21959","DEBIAN-CVE-2025-21959","GHSA-hwhh-xm47-jghm","ROOT-OS-UBUNTU-2404-CVE-2025-21959","UBUNTU-CVE-2025-21959"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["data_read"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel netfilter","requires_auth":"none","summary":"An uninitialized memory bug in the Linux kernel netfilter module allows attackers to read sensitive kernel memory via crafted network packets.","user_interaction":"not_required","vuln_class":"information_disclosure"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":7.3,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","version":"3.1"},"cwes":[{"id":"CWE-908","name":"Use of Uninitialized Resource"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conncount: Fully initialize struct nf_conncount_tuple in insert_tree()\n\nSince commit b36e4523d4d5 (\"netfilter: nf_conncount: fix garbage\ncollection confirm race\"), `cpu` and `jiffies32` were introduced to\nthe struct nf_conncount_tuple.\n\nThe commit made nf_conncount_add() initialize `conn-\u003ecpu` and\n`conn-\u003ejiffies32` when allocating the struct.\nIn contrast, count_tree() was not changed to initialize them.\n\nBy commit 34848d5c896e (\"netfilter: nf_conncount: Split insert and\ntraversal\"), count_tree() was split and the relevant allocation\ncode now resides in insert_tree().\nInitialize `conn-\u003ecpu` and `conn-\u003ejiffies32` in insert_tree().\n\nBUG: KMSAN: uninit-value in find_or_evict net/netfilter/nf_conncount.c:117 [inline]\nBUG: KMSAN: uninit-value in __nf_conncount_add+0xd9c/0x2850 net/netfilter/nf_conncount.c:143\n find_or_evict net/netfilter/nf_conncount.c:117 [inline]\n __nf_conncount_add+0xd9c/0x2850 net/netfilter/nf_conncount.c:143\n count_tree net/netfilter/nf_conncount.c:438 [inline]\n nf_conncount_count+0x82f/0x1e80 net/netfilter/nf_conncount.c:521\n connlimit_mt+0x7f6/0xbd0 net/netfilter/xt_connlimit.c:72\n __nft_match_eval net/netfilter/nft_compat.c:403 [inline]\n nft_match_eval+0x1a5/0x300 net/netfilter/nft_compat.c:433\n expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline]\n nft_do_chain+0x426/0x2290 net/netfilter/nf_tables_core.c:288\n nft_do_chain_ipv4+0x1a5/0x230 net/netfilter/nft_chain_filter.c:23\n nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]\n nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626\n nf_hook_slow_list+0x24d/0x860 net/netfilter/core.c:663\n NF_HOOK_LIST include/linux/netfilter.h:350 [inline]\n ip_sublist_rcv+0x17b7/0x17f0 net/ipv4/ip_input.c:633\n ip_list_rcv+0x9ef/0xa40 net/ipv4/ip_input.c:669\n __netif_receive_skb_list_ptype net/core/dev.c:5936 [inline]\n __netif_receive_skb_list_core+0x15c5/0x1670 net/core/dev.c:5983\n __netif_receive_skb_list net/core/dev.c:6035 [inline]\n netif_receive_skb_list_internal+0x1085/0x1700 net/core/dev.c:6126\n netif_receive_skb_list+0x5a/0x460 net/core/dev.c:6178\n xdp_recv_frames net/bpf/test_run.c:280 [inline]\n xdp_test_run_batch net/bpf/test_run.c:361 [inline]\n bpf_test_run_xdp_live+0x2e86/0x3480 net/bpf/test_run.c:390\n bpf_prog_test_run_xdp+0xf1d/0x1ae0 net/bpf/test_run.c:1316\n bpf_prog_test_run+0x5e5/0xa30 kernel/bpf/syscall.c:4407\n __sys_bpf+0x6aa/0xd90 kernel/bpf/syscall.c:5813\n __do_sys_bpf kernel/bpf/syscall.c:5902 [inline]\n __se_sys_bpf kernel/bpf/syscall.c:5900 [inline]\n __ia32_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5900\n ia32_sys_call+0x394d/0x4180 arch/x86/include/generated/asm/syscalls_32.h:358\n do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]\n __do_fast_syscall_32+0xb0/0x110 arch/x86/entry/common.c:387\n do_fast_syscall_32+0x38/0x80 arch/x86/entry/common.c:412\n do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:450\n entry_SYSENTER_compat_after_hwframe+0x84/0x8e\n\nUninit was created at:\n slab_post_alloc_hook mm/slub.c:4121 [inline]\n slab_alloc_node mm/slub.c:4164 [inline]\n kmem_cache_alloc_noprof+0x915/0xe10 mm/slub.c:4171\n insert_tree net/netfilter/nf_conncount.c:372 [inline]\n count_tree net/netfilter/nf_conncount.c:450 [inline]\n nf_conncount_count+0x1415/0x1e80 net/netfilter/nf_conncount.c:521\n connlimit_mt+0x7f6/0xbd0 net/netfilter/xt_connlimit.c:72\n __nft_match_eval net/netfilter/nft_compat.c:403 [inline]\n nft_match_eval+0x1a5/0x300 net/netfilter/nft_compat.c:433\n expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline]\n nft_do_chain+0x426/0x2290 net/netfilter/nf_tables_core.c:288\n nft_do_chain_ipv4+0x1a5/0x230 net/netfilter/nft_chain_filter.c:23\n nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]\n nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626\n nf_hook_slow_list+0x24d/0x860 net/netfilter/core.c:663\n NF_HOOK_LIST include/linux/netfilter.h:350 [inline]\n ip_sublist_rcv+0x17b7/0x17f0 net/ipv4/ip_input.c:633\n ip_list_rcv+0x9ef/0xa40 net/ip\n---truncated---","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":"netfilter: nf_conncount: Fully initialize struct nf_conncount_tuple in insert_tree()","id":"CVE-2025-21959","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"information_disclosure","year":"2025"},"n_packages":0,"n_references":8,"next":{"headline":"eth: bnxt: do not update checksum in bnxt_xdp_build_skb()","id":"CVE-2025-21960"},"packages":[],"prev":{"headline":"Revert \"openvswitch: switch to per-action label counting in conntrack\"","id":"CVE-2025-21958"},"products":["Linux"],"published":"2025-04-01","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":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-15","vendors":["Linux"]},"summary":"An uninitialized memory bug in the Linux kernel netfilter module allows attackers to read sensitive kernel memory via crafted network packets.","url":"https://insights.sbomify.com/CVE-2025-21959/"}