{ "document": { "category": "csaf_base", "csaf_version": "2.0", "distribution": { "tlp": { "label": "WHITE" } }, "lang": "en", "notes": [ { "category": "legal_disclaimer", "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings." } ], "publisher": { "category": "coordinator", "contact_details": "cert@ncsc.nl", "name": "National Cyber Security Centre", "namespace": "https://www.ncsc.nl/" }, "title": "CVE-2026-23397", "tracking": { "current_release_date": "2026-03-28T12:23:05.959368Z", "generator": { "date": "2026-02-17T15:00:00Z", "engine": { "name": "V.E.L.M.A", "version": "1.7" } }, "id": "CVE-2026-23397", "initial_release_date": "2026-03-26T10:38:40.790805Z", "revision_history": [ { "date": "2026-03-26T10:38:40.790805Z", "number": "1", "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| Products created (6).| Products connected (8).| References created (6)." }, { "date": "2026-03-26T10:38:44.174661Z", "number": "2", "summary": "NCSC Score created." }, { "date": "2026-03-26T11:25:50.626469Z", "number": "3", "summary": "Source created.| CVE status created. (valid)| Description created for source.| References created (6)." }, { "date": "2026-03-26T13:06:16.495228Z", "number": "4", "summary": "Source connected.| CVE status created. (valid)| Products connected (1).| References created (6)." }, { "date": "2026-03-26T13:06:19.039352Z", "number": "5", "summary": "NCSC Score updated." }, { "date": "2026-03-26T15:22:12.747478Z", "number": "6", "summary": "Source connected.| CVE status created. (valid)| EPSS created." }, { "date": "2026-03-26T15:22:14.807618Z", "number": "7", "summary": "NCSC Score updated." }, { "date": "2026-03-26T18:44:08.958704Z", "number": "8", "summary": "Source created.| CVE status created. (valid)| Products connected (2)." }, { "date": "2026-03-26T18:44:12.795717Z", "number": "9", "summary": "NCSC Score updated." }, { "date": "2026-03-27T06:43:45.588234Z", "number": "10", "summary": "Description created for source." }, { "date": "2026-03-27T06:43:47.238187Z", "number": "11", "summary": "NCSC Score updated." }, { "date": "2026-03-27T19:40:53.189034Z", "number": "12", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (13).| Product Identifiers created (5).| Product Remediations created (13).| References created (3).| CWES updated (1).| Vendor_assessment created." }, { "date": "2026-03-27T19:40:56.352776Z", "number": "13", "summary": "NCSC Score updated." }, { "date": "2026-03-27T19:41:03.207114Z", "number": "14", "summary": "Source connected.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (1)." }, { "date": "2026-03-27T19:41:08.515571Z", "number": "15", "summary": "NCSC Score updated." }, { "date": "2026-03-28T12:20:13.652085Z", "number": "16", "summary": "Product Remediations created (1)." }, { "date": "2026-03-28T12:20:15.331416Z", "number": "17", "summary": "NCSC Score updated." } ], "status": "interim", "version": "17" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:git/11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384|<224f4678812e1a7bc8341bcb666773a0aec5ea6f", "product": { "name": "vers:git/11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384|<224f4678812e1a7bc8341bcb666773a0aec5ea6f", "product_id": "CSAFPID-5916214" } }, { "category": "product_version_range", "name": "vers:git/11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384|<3932620c04c2938c93c0890c225960d3d34ba355", "product": { "name": "vers:git/11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384|<3932620c04c2938c93c0890c225960d3d34ba355", "product_id": "CSAFPID-5916216" } }, { "category": "product_version_range", "name": "vers:git/11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384|<4c6aa008b913e808c4f4d3cde36cb1d9bb5967c6", "product": { "name": "vers:git/11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384|<4c6aa008b913e808c4f4d3cde36cb1d9bb5967c6", "product_id": "CSAFPID-5916217" } }, { "category": "product_version_range", "name": "vers:git/11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384|optp 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 < 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 \"< 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->optsize == 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.", "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/23xxx/CVE-2026-23397.json" }, { "category": "description", "text": "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->optp 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 < 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 \"< 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->optsize == 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.", "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-23397" }, { "category": "description", "text": "nfnetlink\\_osf: validate individual option lengths in fingerprints", "title": "microsoft - https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2026-Mar" }, { "category": "description", "text": "In the Linux kernel, the following vulnerability has been resolved: nfnetlink_osf: validate individual option lengths in fingerprints nfnl_osf_add_callback() validates opt_num bounds and string NUL-termination but does not check individual option length fields. A zero-length option causes nf_osf_match_one() to enter the option matching loop even when foptsize sums to zero, which matches packets with no TCP options where ctx->optp is NULL: Oops: general protection fault KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:nf_osf_match_one (net/netfilter/nfnetlink_osf.c:98) Call Trace: nf_osf_match (net/netfilter/nfnetlink_osf.c:227) xt_osf_match_packet (net/netfilter/xt_osf.c:32) ipt_do_table (net/ipv4/netfilter/ip_tables.c:293) nf_hook_slow (net/netfilter/core.c:623) ip_local_deliver (net/ipv4/ip_input.c:262) ip_rcv (net/ipv4/ip_input.c:573) Additionally, an MSS option (kind=2) with length < 4 causes out-of-bounds reads when nf_osf_match_one() unconditionally accesses optp[2] and optp[3] for MSS value extraction. While RFC 9293 section 3.2 specifies that the MSS option is always exactly 4 bytes (Kind=2, Length=4), the check uses \"< 4\" rather than \"!= 4\" because lengths greater than 4 do not cause memory safety issues -- the buffer is guaranteed to be at least foptsize bytes by the ctx->optsize == foptsize check. Reject fingerprints where any option has zero length, or where an MSS option has length less than 4, at add time rather than trusting these values in the packet matching hot path.", "title": "debian - https://security-tracker.debian.org/tracker/CVE-2026-23397" }, { "category": "description", "text": "In the Linux kernel, the following vulnerability has been resolved:\nnfnetlink_osf: validate individual option lengths in fingerprints\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->optp is NULL:\nOops: general protection fault\nKASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\nRIP: 0010:nf_osf_match_one (net/netfilter/nfnetlink_osf.c:98)\nCall Trace:\nnf_osf_match (net/netfilter/nfnetlink_osf.c:227)\nxt_osf_match_packet (net/netfilter/xt_osf.c:32)\nipt_do_table (net/ipv4/netfilter/ip_tables.c:293)\nnf_hook_slow (net/netfilter/core.c:623)\nip_local_deliver (net/ipv4/ip_input.c:262)\nip_rcv (net/ipv4/ip_input.c:573)\nAdditionally, an MSS option (kind=2) with length < 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 \"< 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->optsize == foptsize check.\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.\nA flaw was found in the nfnetlink_osf module of the Linux kernel. A remote attacker could send specially crafted network packets containing malformed options, such as zero-length options or a Maximum Segment Size (MSS) option with an invalid length. This could lead to a system crash, resulting in a Denial of Service (DoS), which makes the system unavailable to legitimate users.\nExploitation of this vulnerability requires CAP_NET_ADMIN privileges to load the malicious OS fingerprint via nfnl_osf_add_callback(). Network packets then trigger the crash during fingerprint matching. Since setting up the vulnerable condition requires elevated privileges, and the impact is limited to denial of service, the risk is reduced compared to a purely remote attack.", "title": "redhat - https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-23397.json" }, { "category": "other", "text": "0.00024", "title": "EPSS" }, { "category": "other", "text": "4.4", "title": "NCSC Score" }, { "category": "other", "text": "Is related to an uncommon cwe id, VENDOR FIX as product remediation category", "title": "NCSC Score top increasing factors" }, { "category": "other", "text": "Is related to a product by vendor Linux, Is related to a product by vendor Debian, The value of the most recent EPSS score", "title": "NCSC Score top decreasing factors" }, { "category": "details", "text": "Severity: 2\n", "title": "Vendor assessment" } ], "product_status": { "known_affected": [ "CSAFPID-1467543", "CSAFPID-5916213", "CSAFPID-5916214", "CSAFPID-5916215", "CSAFPID-5916216", "CSAFPID-5916217", "CSAFPID-5916218", "CSAFPID-1330297", "CSAFPID-2036021", "CSAFPID-2036024", "CSAFPID-1439319", "CSAFPID-1453381", "CSAFPID-1453382", "CSAFPID-2858634", "CSAFPID-2858635", "CSAFPID-5761981" ], "known_not_affected": [ "CSAFPID-1467544", "CSAFPID-5904647", "CSAFPID-5904654", "CSAFPID-5904671", "CSAFPID-5905005", "CSAFPID-5905006", "CSAFPID-5905027", "CSAFPID-1439315", "CSAFPID-1439317", "CSAFPID-1439321", "CSAFPID-1453376", "CSAFPID-1453377", "CSAFPID-1453378", "CSAFPID-1453379", "CSAFPID-1453380" ] }, "references": [ { "category": "external", "summary": "Source - cveprojectv5", "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/23xxx/CVE-2026-23397.json" }, { "category": "external", "summary": "Source - nvd", "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-23397" }, { "category": "external", "summary": "Source - certbundde", "url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-0879.json" }, { "category": "external", "summary": "Source - first", "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0" }, { "category": "external", "summary": "Source - debian", "url": "https://security-tracker.debian.org/tracker/CVE-2026-23397" }, { "category": "external", "summary": "Source - redhat", "url": "https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-23397.json" }, { "category": "external", "summary": "Source - microsoft", "url": "https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2026-Mar" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://git.kernel.org/stable/c/aa0574182c46963c3cdb8cde46ec93aca21100d8" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://git.kernel.org/stable/c/224f4678812e1a7bc8341bcb666773a0aec5ea6f" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://git.kernel.org/stable/c/ec8bf0571b142f29dc0b68ae2ac3952f7a464b38" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://git.kernel.org/stable/c/3932620c04c2938c93c0890c225960d3d34ba355" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://git.kernel.org/stable/c/4c6aa008b913e808c4f4d3cde36cb1d9bb5967c6" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://git.kernel.org/stable/c/dbdfaae9609629a9569362e3b8f33d0a20fd783c" }, { "category": "external", "summary": "Reference - certbundde", "url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-0879.json" }, { "category": "external", "summary": "Reference - certbundde", "url": "https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-0879" }, { "category": "external", "summary": "Reference - certbundde", "url": "https://lore.kernel.org/linux-cve-announce/" }, { "category": "external", "summary": "Reference - certbundde", "url": "https://lore.kernel.org/linux-cve-announce/2026032631-CVE-2026-23396-6447@gregkh/" }, { "category": "external", "summary": "Reference - certbundde", "url": "https://lore.kernel.org/linux-cve-announce/2026032634-CVE-2026-23397-d4f0@gregkh/" }, { "category": "external", "summary": "Reference - certbundde", "url": "https://lore.kernel.org/linux-cve-announce/2026032634-CVE-2026-23398-df1e@gregkh/" }, { "category": "external", "summary": "Reference - redhat", "url": "https://www.cve.org/CVERecord?id=CVE-2026-23397" }, { "category": "external", "summary": "Reference - redhat", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23397" }, { "category": "external", "summary": "Reference - redhat", "url": "https://lore.kernel.org/linux-cve-announce/2026032634-CVE-2026-23397-d4f0@gregkh/T" } ], "remediations": [ { "category": "mitigation", "details": "To mitigate this issue, prevent the nfnetlink_osf and xt_osf modules from being loaded. See https://access.redhat.com/solutions/41278 for instructions.", "product_ids": [ "CSAFPID-1439315", "CSAFPID-1439317", "CSAFPID-1439319", "CSAFPID-1439321", "CSAFPID-1453376", "CSAFPID-1453377", "CSAFPID-1453378", "CSAFPID-1453379", "CSAFPID-1453380", "CSAFPID-1453381", "CSAFPID-1453382", "CSAFPID-2858634", "CSAFPID-2858635" ] }, { "category": "vendor_fix", "details": "CBL-Mariner Releases", "product_ids": [ "CSAFPID-5761981" ] } ], "scores": [ { "cvss_v3": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H", "baseScore": 4.4, "baseSeverity": "MEDIUM" }, "products": [ "CSAFPID-1330297", "CSAFPID-1439319", "CSAFPID-1453381", "CSAFPID-1453382", "CSAFPID-1467543", "CSAFPID-2036021", "CSAFPID-2036024", "CSAFPID-2858634", "CSAFPID-2858635", "CSAFPID-5761981", "CSAFPID-5916213", "CSAFPID-5916214", "CSAFPID-5916215", "CSAFPID-5916216", "CSAFPID-5916217", "CSAFPID-5916218" ] } ], "title": "CVE-2026-23397" } ] }