{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-53080 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-53080 is a medium-severity vulnerability in Linux kernel, published on 24 Jun 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-2026-53080 and fix it if it is affected.\n\nWhat it is: CVE-2026-53080 is a medium-severity vulnerability in Linux kernel, published on 24 Jun 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-2026-53080 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-2026-53080/ (Markdown: https://insights.sbomify.com/CVE-2026-53080/index.md)","id":"CVE-2026-53080","markdown":"https://insights.sbomify.com/CVE-2026-53080/index.md","name":"CVE-2026-53080","record":{"aliases":["AZL-90789","BELL-CVE-2026-53080","DEBIAN-CVE-2026-53080","GHSA-6vxh-r6p9-w9ch","ROOT-OS-UBUNTU-2204-CVE-2026-53080","ROOT-OS-UBUNTU-2404-CVE-2026-53080","UBUNTU-CVE-2026-53080"],"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 NULL pointer dereference in the Linux kernel's cls_fw classifier allows local attackers to cause a system crash via crafted network traffic.","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\nnet/sched: cls_fw: fix NULL dereference of \"old\" filters before change()\n\nLike pointed out by Sashiko [1], since commit ed76f5edccc9 (\"net: sched:\nprotect filter_chain list with filter_chain_lock mutex\") TC filters are\nadded to a shared block and published to datapath before their -\u003echange()\nfunction is called. This is a problem for cls_fw: an invalid filter\ncreated with the \"old\" method can still classify some packets before it\nis destroyed by the validation logic added by Xiang.\nTherefore, insisting with repeated runs of the following script:\n\n # ip link add dev crash0 type dummy\n # ip link set dev crash0 up\n # mausezahn  crash0 -c 100000 -P 10 \\\n \u003e -A 4.3.2.1 -B 1.2.3.4 -t udp \"dp=1234\" -q \u0026\n # sleep 1\n # tc qdisc add dev crash0 egress_block 1 clsact\n # tc filter add block 1 protocol ip prio 1 matchall \\\n \u003e action skbedit mark 65536 continue\n # tc filter add block 1 protocol ip prio 2 fw\n # ip link del dev crash0\n\ncan still make fw_classify() hit the WARN_ON() in [2]:\n\n WARNING: ./include/net/pkt_cls.h:88 at fw_classify+0x244/0x250 [cls_fw], CPU#18: mausezahn/1399\n Modules linked in: cls_fw(E) act_skbedit(E)\n CPU: 18 UID: 0 PID: 1399 Comm: mausezahn Tainted: G            E       7.0.0-rc6-virtme #17 PREEMPT(full)\n Tainted: [E]=UNSIGNED_MODULE\n Hardware name: Red Hat KVM, BIOS 1.16.3-2.el9 04/01/2014\n RIP: 0010:fw_classify+0x244/0x250 [cls_fw]\n Code: 5c 49 c7 45 00 00 00 00 00 41 5d 41 5e 41 5f 5d c3 cc cc cc cc 5b b8 ff ff ff ff 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc 90 \u003c0f\u003e 0b 90 eb a0 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90\n RSP: 0018:ffffd1b7026bf8a8 EFLAGS: 00010202\n RAX: ffff8c5ac9c60800 RBX: ffff8c5ac99322c0 RCX: 0000000000000004\n RDX: 0000000000000001 RSI: ffff8c5b74d7a000 RDI: ffff8c5ac8284f40\n RBP: ffffd1b7026bf8d0 R08: 0000000000000000 R09: ffffd1b7026bf9b0\n R10: 00000000ffffffff R11: 0000000000000000 R12: 0000000000010000\n R13: ffffd1b7026bf930 R14: ffff8c5ac8284f40 R15: 0000000000000000\n FS:  00007fca40c37740(0000) GS:ffff8c5b74d7a000(0000) knlGS:0000000000000000\n CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007fca40e822a0 CR3: 0000000005ca0001 CR4: 0000000000172ef0\n Call Trace:\n  \u003cTASK\u003e\n  tcf_classify+0x17d/0x5c0\n  tc_run+0x9d/0x150\n  __dev_queue_xmit+0x2ab/0x14d0\n  ip_finish_output2+0x340/0x8f0\n  ip_output+0xa4/0x250\n  raw_sendmsg+0x147d/0x14b0\n  __sys_sendto+0x1cc/0x1f0\n  __x64_sys_sendto+0x24/0x30\n  do_syscall_64+0x126/0xf80\n  entry_SYSCALL_64_after_hwframe+0x77/0x7f\n RIP: 0033:0x7fca40e822ba\n Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 15 b8 2c 00 00 00 0f 05 \u003c48\u003e 3d 00 f0 ff ff 77 7e c3 0f 1f 44 00 00 41 54 48 83 ec 30 44 89\n RSP: 002b:00007ffc248a42c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c\n RAX: ffffffffffffffda RBX: 000055ef233289d0 RCX: 00007fca40e822ba\n RDX: 000000000000001e RSI: 000055ef23328c30 RDI: 0000000000000003\n RBP: 000055ef233289d0 R08: 00007ffc248a42d0 R09: 0000000000000010\n R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000001e\n R13: 00000000000186a0 R14: 0000000000000000 R15: 00007fca41043000\n  \u003c/TASK\u003e\n irq event stamp: 1045778\n hardirqs last  enabled at (1045784): [\u003cffffffff864ec042\u003e] __up_console_sem+0x52/0x60\n hardirqs last disabled at (1045789): [\u003cffffffff864ec027\u003e] __up_console_sem+0x37/0x60\n softirqs last  enabled at (1045426): [\u003cffffffff874d48c7\u003e] __alloc_skb+0x207/0x260\n softirqs last disabled at (1045434): [\u003cffffffff874fe8f8\u003e] __dev_queue_xmit+0x78/0x14d0\n\nThen, because of the value in the packet's mark, dereference on 'q-\u003ehandle'\nwith NULL 'q' occurs:\n\n BUG: kernel NULL  pointer dereference, address: 0000000000000038\n [...]\n RIP: 0010:fw_classify+0x1fe/0x250 [cls_fw]\n [...]\n\nSkip \"old-style\" classification on shared blocks, so that the NULL\ndereference is fixed and WARN_ON() is not hit anymore in the short\nlifetime of invalid cls_fw \"old-style\" filters.\n\n[1] https://sashiko.dev/#/patchset/2\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":"net/sched: cls_fw: fix NULL dereference of \"old\" filters before change()","id":"CVE-2026-53080","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":8,"next":{"headline":"bpf: Enforce regsafe base id consistency for BPF_ADD_CONST scalars","id":"CVE-2026-53081"},"packages":[],"prev":{"headline":"net_sched: fix skb memory leak in deferred qdisc drops","id":"CVE-2026-53079"},"products":["Linux"],"published":"2026-06-24","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":"2026-10-15","vendors":["Linux"]},"summary":"A NULL pointer dereference in the Linux kernel's cls_fw classifier allows local attackers to cause a system crash via crafted network traffic.","url":"https://insights.sbomify.com/CVE-2026-53080/"}