{"api_version":"1","generated_at":"2026-04-19T01:11:34+00:00","cve":"CVE-2026-23398","urls":{"html":"https://cve.report/CVE-2026-23398","api":"https://cve.report/api/cve/CVE-2026-23398.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-23398","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-23398"},"summary":{"title":"icmp: fix NULL pointer dereference in icmp_tag_validation()","description":"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  <IRQ>\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  </IRQ>\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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-03-26 11:16:19","updated_at":"2026-04-18 09:16:24"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/b61529c357f1ee4d64836eb142a542d2e7ad67ce","name":"https://git.kernel.org/stable/c/b61529c357f1ee4d64836eb142a542d2e7ad67ce","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1e4e2f5e48cec0cccaea9815fb9486c084ba41e2","name":"https://git.kernel.org/stable/c/1e4e2f5e48cec0cccaea9815fb9486c084ba41e2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/571d9d7b650f02d1e38c01128817868bceac9edd","name":"https://git.kernel.org/stable/c/571d9d7b650f02d1e38c01128817868bceac9edd","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d938dd5a0ad780c891ea3bc94cae7405f11e618a","name":"https://git.kernel.org/stable/c/d938dd5a0ad780c891ea3bc94cae7405f11e618a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9647e99d2a617c355d2b378be0ff6d0e848fd579","name":"https://git.kernel.org/stable/c/9647e99d2a617c355d2b378be0ff6d0e848fd579","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/614aefe56af8e13331e50220c936fc0689cf5675","name":"https://git.kernel.org/stable/c/614aefe56af8e13331e50220c936fc0689cf5675","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d783fa413c702ff0f8f8bea63f862e28eeaf39e3","name":"https://git.kernel.org/stable/c/d783fa413c702ff0f8f8bea63f862e28eeaf39e3","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1f9f2c6d4b2a613b7756fc5679c5116ba2ca0161","name":"https://git.kernel.org/stable/c/1f9f2c6d4b2a613b7756fc5679c5116ba2ca0161","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-23398","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23398","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e 571d9d7b650f02d1e38c01128817868bceac9edd git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e d783fa413c702ff0f8f8bea63f862e28eeaf39e3 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e 1f9f2c6d4b2a613b7756fc5679c5116ba2ca0161 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e b61529c357f1ee4d64836eb142a542d2e7ad67ce git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.203 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.167 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.130 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.78 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.20 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.10 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"23398","cve":"CVE-2026-23398","epss":"0.000320000","percentile":"0.090980000","score_date":"2026-04-18","updated_at":"2026-04-19 00:10:43"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/ipv4/icmp.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"571d9d7b650f02d1e38c01128817868bceac9edd","status":"affected","version":"8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e","versionType":"git"},{"lessThan":"d783fa413c702ff0f8f8bea63f862e28eeaf39e3","status":"affected","version":"8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e","versionType":"git"},{"lessThan":"1f9f2c6d4b2a613b7756fc5679c5116ba2ca0161","status":"affected","version":"8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e","versionType":"git"},{"lessThan":"b61529c357f1ee4d64836eb142a542d2e7ad67ce","status":"affected","version":"8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e","versionType":"git"},{"lessThan":"9647e99d2a617c355d2b378be0ff6d0e848fd579","status":"affected","version":"8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e","versionType":"git"},{"lessThan":"d938dd5a0ad780c891ea3bc94cae7405f11e618a","status":"affected","version":"8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e","versionType":"git"},{"lessThan":"1e4e2f5e48cec0cccaea9815fb9486c084ba41e2","status":"affected","version":"8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e","versionType":"git"},{"lessThan":"614aefe56af8e13331e50220c936fc0689cf5675","status":"affected","version":"8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/ipv4/icmp.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"3.14"},{"lessThan":"3.14","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.253","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.203","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.167","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.130","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.78","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.20","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.10","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.253","versionStartIncluding":"3.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.203","versionStartIncluding":"3.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.167","versionStartIncluding":"3.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.130","versionStartIncluding":"3.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.78","versionStartIncluding":"3.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.20","versionStartIncluding":"3.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.10","versionStartIncluding":"3.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0","versionStartIncluding":"3.14","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"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  <IRQ>\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  </IRQ>\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."}],"providerMetadata":{"dateUpdated":"2026-04-18T08:58:33.834Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/571d9d7b650f02d1e38c01128817868bceac9edd"},{"url":"https://git.kernel.org/stable/c/d783fa413c702ff0f8f8bea63f862e28eeaf39e3"},{"url":"https://git.kernel.org/stable/c/1f9f2c6d4b2a613b7756fc5679c5116ba2ca0161"},{"url":"https://git.kernel.org/stable/c/b61529c357f1ee4d64836eb142a542d2e7ad67ce"},{"url":"https://git.kernel.org/stable/c/9647e99d2a617c355d2b378be0ff6d0e848fd579"},{"url":"https://git.kernel.org/stable/c/d938dd5a0ad780c891ea3bc94cae7405f11e618a"},{"url":"https://git.kernel.org/stable/c/1e4e2f5e48cec0cccaea9815fb9486c084ba41e2"},{"url":"https://git.kernel.org/stable/c/614aefe56af8e13331e50220c936fc0689cf5675"}],"title":"icmp: fix NULL pointer dereference in icmp_tag_validation()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-23398","datePublished":"2026-03-26T10:22:50.606Z","dateReserved":"2026-01-13T15:37:46.012Z","dateUpdated":"2026-04-18T08:58:33.834Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-03-26 11:16:19","lastModifiedDate":"2026-04-18 09:16:24","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"23398","Ordinal":"1","Title":"icmp: fix NULL pointer dereference in icmp_tag_validation()","CVE":"CVE-2026-23398","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"23398","Ordinal":"1","NoteData":"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  <IRQ>\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  </IRQ>\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.","Type":"Description","Title":"icmp: fix NULL pointer dereference in icmp_tag_validation()"}]}}}