{ "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-2026-23398", "tracking": { "current_release_date": "2026-03-30T18:33:08.932483Z", "generator": { "date": "2026-02-17T15:00:00Z", "engine": { "name": "V.E.L.M.A", "version": "1.7" } }, "id": "CVE-2026-23398", "initial_release_date": "2026-03-26T10:38:42.228260Z", "revision_history": [ { "date": "2026-03-26T10:38:42.228260Z", "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": "2026-03-26T10:38:45.357387Z", "number": "2", "summary": "NCSC Score created." }, { "date": "2026-03-26T11:25:51.062721Z", "number": "3", "summary": "Source created.| CVE status created. (valid)| Description created for source.| References created (6)." }, { "date": "2026-03-26T13:06:16.743761Z", "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": "2026-03-26T15:22:12.575413Z", "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": "2026-03-26T18:44:09.316293Z", "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": "2026-03-27T06:43:45.936144Z", "number": "10", "summary": "Description created for source." }, { "date": "2026-03-27T06:43:48.540648Z", "number": "11", "summary": "NCSC Score updated." }, { "date": "2026-03-27T19:40:32.967818Z", "number": "12", "summary": "Source connected.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (1)." }, { "date": "2026-03-27T19:40:43.392164Z", "number": "13", "summary": "NCSC Score updated." }, { "date": "2026-03-27T19:40:50.828117Z", "number": "14", "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": "2026-03-27T19:40:55.196785Z", "number": "15", "summary": "NCSC Score updated." }, { "date": "2026-03-28T12:19:56.436690Z", "number": "16", "summary": "Product Remediations created (1)." }, { "date": "2026-03-28T12:19:58.612272Z", "number": "17", "summary": "NCSC Score updated." }, { "date": "2026-03-30T18:29:03.338258Z", "number": "18", "summary": "NCSC Score updated." } ], "status": "interim", "version": "18" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:git/8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e|<1e4e2f5e48cec0cccaea9815fb9486c084ba41e2", "product": { "name": "vers:git/8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e|<1e4e2f5e48cec0cccaea9815fb9486c084ba41e2", "product_id": "CSAFPID-5916223" } }, { "category": "product_version_range", "name": "vers:git/8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e|<1f9f2c6d4b2a613b7756fc5679c5116ba2ca0161", "product": { "name": "vers:git/8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e|<1f9f2c6d4b2a613b7756fc5679c5116ba2ca0161", "product_id": "CSAFPID-5916219" } }, { "category": "product_version_range", "name": "vers:git/8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e|<614aefe56af8e13331e50220c936fc0689cf5675", "product": { "name": "vers:git/8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e|<614aefe56af8e13331e50220c936fc0689cf5675", "product_id": "CSAFPID-5916224" } }, { "category": "product_version_range", "name": "vers:git/8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e|<9647e99d2a617c355d2b378be0ff6d0e848fd579", "product": { "name": "vers:git/8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e|<9647e99d2a617c355d2b378be0ff6d0e848fd579", "product_id": "CSAFPID-5916221" } }, { "category": "product_version_range", "name": "vers:git/8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e|\n icmp_rcv (net/ipv4/icmp.c:1527)\n ip_protocol_deliver_rcu (net/ipv4/ip_input.c:207)\n ip_local_deliver_finish (net/ipv4/ip_input.c:242)\n ip_local_deliver (net/ipv4/ip_input.c:262)\n ip_rcv (net/ipv4/ip_input.c:573)\n __netif_receive_skb_one_core (net/core/dev.c:6164)\n process_backlog (net/core/dev.c:6628)\n handle_softirqs (kernel/softirq.c:561)\n \n\nAdd a NULL check before accessing icmp_strict_tag_validation. If the\nprotocol has no registered handler, return false since it cannot\nperform strict tag validation.", "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/23xxx/CVE-2026-23398.json" }, { "category": "description", "text": "In the Linux kernel, the following vulnerability has been resolved:\n\nicmp: fix NULL pointer dereference in icmp_tag_validation()\n\nicmp_tag_validation() unconditionally dereferences the result of\nrcu_dereference(inet_protos[proto]) without checking for NULL.\nThe inet_protos[] array is sparse -- only about 15 of 256 protocol\nnumbers have registered handlers. When ip_no_pmtu_disc is set to 3\n(hardened PMTU mode) and the kernel receives an ICMP Fragmentation\nNeeded error with a quoted inner IP header containing an unregistered\nprotocol number, the NULL dereference causes a kernel panic in\nsoftirq context.\n\n Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN NOPTI\n KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]\n RIP: 0010:icmp_unreach (net/ipv4/icmp.c:1085 net/ipv4/icmp.c:1143)\n Call Trace:\n \n icmp_rcv (net/ipv4/icmp.c:1527)\n ip_protocol_deliver_rcu (net/ipv4/ip_input.c:207)\n ip_local_deliver_finish (net/ipv4/ip_input.c:242)\n ip_local_deliver (net/ipv4/ip_input.c:262)\n ip_rcv (net/ipv4/ip_input.c:573)\n __netif_receive_skb_one_core (net/core/dev.c:6164)\n process_backlog (net/core/dev.c:6628)\n handle_softirqs (kernel/softirq.c:561)\n \n\nAdd a NULL check before accessing icmp_strict_tag_validation. If the\nprotocol has no registered handler, return false since it cannot\nperform strict tag validation.", "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-23398" }, { "category": "description", "text": "In the Linux kernel, the following vulnerability has been resolved: icmp: fix NULL pointer dereference in icmp_tag_validation() icmp_tag_validation() unconditionally dereferences the result of rcu_dereference(inet_protos[proto]) without checking for NULL. The inet_protos[] array is sparse -- only about 15 of 256 protocol numbers have registered handlers. When ip_no_pmtu_disc is set to 3 (hardened PMTU mode) and the kernel receives an ICMP Fragmentation Needed error with a quoted inner IP header containing an unregistered protocol number, the NULL dereference causes a kernel panic in softirq context. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] RIP: 0010:icmp_unreach (net/ipv4/icmp.c:1085 net/ipv4/icmp.c:1143) Call Trace: icmp_rcv (net/ipv4/icmp.c:1527) ip_protocol_deliver_rcu (net/ipv4/ip_input.c:207) ip_local_deliver_finish (net/ipv4/ip_input.c:242) ip_local_deliver (net/ipv4/ip_input.c:262) ip_rcv (net/ipv4/ip_input.c:573) __netif_receive_skb_one_core (net/core/dev.c:6164) process_backlog (net/core/dev.c:6628) handle_softirqs (kernel/softirq.c:561) Add a NULL check before accessing icmp_strict_tag_validation. If the protocol has no registered handler, return false since it cannot perform strict tag validation.", "title": "debian - https://security-tracker.debian.org/tracker/CVE-2026-23398" }, { "category": "description", "text": "icmp: fix NULL pointer dereference in icmp\\_tag\\_validation()", "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:\nicmp: fix NULL pointer dereference in icmp_tag_validation()\nicmp_tag_validation() unconditionally dereferences the result of\nrcu_dereference(inet_protos[proto]) without checking for NULL.\nThe inet_protos[] array is sparse -- only about 15 of 256 protocol\nnumbers have registered handlers. When ip_no_pmtu_disc is set to 3\n(hardened PMTU mode) and the kernel receives an ICMP Fragmentation\nNeeded error with a quoted inner IP header containing an unregistered\nprotocol number, the NULL dereference causes a kernel panic in\nsoftirq context.\nOops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN NOPTI\nKASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]\nRIP: 0010:icmp_unreach (net/ipv4/icmp.c:1085 net/ipv4/icmp.c:1143)\nCall Trace:\n\nicmp_rcv (net/ipv4/icmp.c:1527)\nip_protocol_deliver_rcu (net/ipv4/ip_input.c:207)\nip_local_deliver_finish (net/ipv4/ip_input.c:242)\nip_local_deliver (net/ipv4/ip_input.c:262)\nip_rcv (net/ipv4/ip_input.c:573)\n__netif_receive_skb_one_core (net/core/dev.c:6164)\nprocess_backlog (net/core/dev.c:6628)\nhandle_softirqs (kernel/softirq.c:561)\n\nAdd a NULL check before accessing icmp_strict_tag_validation. If the\nprotocol has no registered handler, return false since it cannot\nperform strict tag validation.\nA flaw was found in the Linux kernel. A remote attacker could trigger a kernel panic, leading to a Denial of Service (DoS), by sending a specially crafted Internet Control Message Protocol (ICMP) Fragmentation Needed error. This occurs when the system is configured for hardened Path Maximum Transmission Unit (PMTU) discovery mode and the ICMP error contains an inner IP header with an unregistered protocol number, causing a null pointer dereference.\nThis vulnerability requires the non-default kernel configuration ip_no_pmtu_disc=3 (hardened PMTU mode). Systems using the default PMTU discovery settings are not affected. While the attack is remotely triggerable via crafted ICMP packets, the specific configuration requirement significantly reduces the attack surface in typical deployments.", "title": "redhat - https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-23398.json" }, { "category": "other", "text": "0.00024", "title": "EPSS" }, { "category": "other", "text": "3.9", "title": "NCSC Score" }, { "category": "other", "text": "VENDOR FIX as product remediation category", "title": "NCSC Score top increasing factors" }, { "category": "other", "text": "The value of the most recent EPSS score, Is related to a product by vendor Linux, Is related to (a version of) product Linux Kernel, Is related to a product by vendor Debian", "title": "NCSC Score top decreasing factors" }, { "category": "details", "text": "Severity: 2\n", "title": "Vendor assessment" } ], "product_status": { "known_affected": [ "CSAFPID-1329080", "CSAFPID-5916219", "CSAFPID-5916220", "CSAFPID-5916221", "CSAFPID-5916222", "CSAFPID-5916223", "CSAFPID-5916224", "CSAFPID-1330297", "CSAFPID-2036021", "CSAFPID-2036024", "CSAFPID-5761981", "CSAFPID-1439317", "CSAFPID-1439319", "CSAFPID-1439321", "CSAFPID-1453376", "CSAFPID-1453379", "CSAFPID-1453380", "CSAFPID-1453381", "CSAFPID-1453382", "CSAFPID-2858634", "CSAFPID-2858635" ], "known_not_affected": [ "CSAFPID-1329081", "CSAFPID-5904647", "CSAFPID-5904654", "CSAFPID-5904671", "CSAFPID-5905005", "CSAFPID-5905006", "CSAFPID-5905027", "CSAFPID-1439315", "CSAFPID-1453377", "CSAFPID-1453378" ] }, "references": [ { "category": "external", "summary": "Source - cveprojectv5", "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/23xxx/CVE-2026-23398.json" }, { "category": "external", "summary": "Source - nvd", "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-23398" }, { "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-2026-23398" }, { "category": "external", "summary": "Source - microsoft", "url": "https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2026-Mar" }, { "category": "external", "summary": "Source - redhat", "url": "https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-23398.json" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://git.kernel.org/stable/c/1f9f2c6d4b2a613b7756fc5679c5116ba2ca0161" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://git.kernel.org/stable/c/b61529c357f1ee4d64836eb142a542d2e7ad67ce" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://git.kernel.org/stable/c/9647e99d2a617c355d2b378be0ff6d0e848fd579" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://git.kernel.org/stable/c/d938dd5a0ad780c891ea3bc94cae7405f11e618a" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://git.kernel.org/stable/c/1e4e2f5e48cec0cccaea9815fb9486c084ba41e2" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://git.kernel.org/stable/c/614aefe56af8e13331e50220c936fc0689cf5675" }, { "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-2026-23398" }, { "category": "external", "summary": "Reference - redhat", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23398" }, { "category": "external", "summary": "Reference - redhat", "url": "https://lore.kernel.org/linux-cve-announce/2026032634-CVE-2026-23398-df1e@gregkh/T" } ], "remediations": [ { "category": "mitigation", "details": "Ensure ip_no_pmtu_disc is not set to 3. Check with: sysctl net.ipv4.ip_no_pmtu_disc. Values 0, 1, or 2 are not affected. If using value 3, consider temporarily switching to value 1 until a kernel update is applied.", "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:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 6.5, "baseSeverity": "MEDIUM" }, "products": [ "CSAFPID-1329080", "CSAFPID-1330297", "CSAFPID-1439317", "CSAFPID-1439319", "CSAFPID-1439321", "CSAFPID-1453376", "CSAFPID-1453379", "CSAFPID-1453380", "CSAFPID-1453381", "CSAFPID-1453382", "CSAFPID-2036021", "CSAFPID-2036024", "CSAFPID-2858634", "CSAFPID-2858635", "CSAFPID-5761981", "CSAFPID-5916219", "CSAFPID-5916220", "CSAFPID-5916221", "CSAFPID-5916222", "CSAFPID-5916223", "CSAFPID-5916224" ] } ], "title": "CVE-2026-23398" } ] }