{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-23397 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-23397 is a high-severity vulnerability in Linux kernel, published on 26 Mar 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-2026-23397 and fix it if it is affected.\n\nWhat it is: CVE-2026-23397 is a high-severity vulnerability in Linux kernel, published on 26 Mar 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-2026-23397 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-2026-23397/ (Markdown: https://insights.sbomify.com/CVE-2026-23397/index.md)","id":"CVE-2026-23397","markdown":"https://insights.sbomify.com/CVE-2026-23397/index.md","name":"CVE-2026-23397","record":{"aliases":["AZL-80850","BELL-CVE-2026-23397","DEBIAN-CVE-2026-23397","GHSA-3rcm-5vqm-53w6","ROOT-OS-DEBIAN-11-CVE-2026-23397","ROOT-OS-DEBIAN-12-CVE-2026-23397","ROOT-OS-DEBIAN-13-CVE-2026-23397","ROOT-OS-UBUNTU-2204-CVE-2026-23397","ROOT-OS-UBUNTU-2404-CVE-2026-23397","UBUNTU-CVE-2026-23397"],"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 missing validation in the Linux kernel's netfilter OS fingerprinting module allows a remote attacker to cause a system crash via crafted TCP packets.","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":7.1,"severity":"high","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-125","name":"Out-of-bounds Read"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfnetlink_osf: validate individual option lengths in fingerprints\n\nnfnl_osf_add_callback() validates opt_num bounds and string\nNUL-termination but does not check individual option length fields.\nA zero-length option causes nf_osf_match_one() to enter the option\nmatching loop even when foptsize sums to zero, which matches packets\nwith no TCP options where ctx-\u003eoptp is NULL:\n\n Oops: general protection fault\n KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\n RIP: 0010:nf_osf_match_one (net/netfilter/nfnetlink_osf.c:98)\n Call Trace:\n  nf_osf_match (net/netfilter/nfnetlink_osf.c:227)\n  xt_osf_match_packet (net/netfilter/xt_osf.c:32)\n  ipt_do_table (net/ipv4/netfilter/ip_tables.c:293)\n  nf_hook_slow (net/netfilter/core.c:623)\n  ip_local_deliver (net/ipv4/ip_input.c:262)\n  ip_rcv (net/ipv4/ip_input.c:573)\n\nAdditionally, an MSS option (kind=2) with length \u003c 4 causes\nout-of-bounds reads when nf_osf_match_one() unconditionally accesses\noptp[2] and optp[3] for MSS value extraction.  While RFC 9293\nsection 3.2 specifies that the MSS option is always exactly 4\nbytes (Kind=2, Length=4), the check uses \"\u003c 4\" rather than\n\"!= 4\" because lengths greater than 4 do not cause memory\nsafety issues -- the buffer is guaranteed to be at least\nfoptsize bytes by the ctx-\u003eoptsize == foptsize check.\n\nReject fingerprints where any option has zero length, or where an MSS\noption has length less than 4, at add time rather than trusting these\nvalues in the packet matching hot path.","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":"nfnetlink_osf: validate individual option lengths in fingerprints","id":"CVE-2026-23397","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":"icmp: fix NULL pointer dereference in icmp_tag_validation()","id":"CVE-2026-23398"},"packages":[],"prev":{"headline":"wifi: mac80211: fix NULL deref in mesh_matches_local()","id":"CVE-2026-23396"},"products":["Linux"],"published":"2026-03-26","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 missing validation in the Linux kernel's netfilter OS fingerprinting module allows a remote attacker to cause a system crash via crafted TCP packets.","url":"https://insights.sbomify.com/CVE-2026-23397/"}