{"api_version":"1","generated_at":"2026-08-17T11:25:35+00:00","cve":"CVE-2026-74550","urls":{"html":"https://cve.report/CVE-2026-74550","api":"https://cve.report/api/cve/CVE-2026-74550.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-74550","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-74550"},"summary":{"title":"net: do not send ICMP/NDISC Redirects when peer allocation fails","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: do not send ICMP/NDISC Redirects when peer allocation fails\n\nWhen inet_getpeer_v4() or inet_getpeer_v6() fails to allocate a peer entry\nunder memory pressure or tree size caps, redirect handlers previously fell\nback to sending un-rate-limited ICMP/NDISC Redirect messages.\n\nIn IPv4, ip_rt_send_redirect() called icmp_send() directly when peer == NULL.\nIn IPv6, ip6_forward() and ndisc_send_redirect() passed a NULL peer into\ninet_peer_xrlim_allow(), which returned true when peer == NULL.\n\nBecause ICMP/NDISC Redirects are not part of the default global rate limit\nmask (sysctl_icmp_ratemask), sending redirects when peer == NULL creates\nan un-rate-limited ICMP packet storm.\n\nFix this by failing closed in ip_rt_send_redirect(), ip6_forward(), and\nndisc_send_redirect() when peer is NULL.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-15 13:18:00","updated_at":"2026-08-17 06:19:52"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.5","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.5","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"baseScore":7.5,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/dbc3791e3b2472e1ccc08947e0f83b443470ff4f","name":"https://git.kernel.org/stable/c/dbc3791e3b2472e1ccc08947e0f83b443470ff4f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/5ec5f00fc606a6df8434948c4552b3cb1176595d","name":"https://git.kernel.org/stable/c/5ec5f00fc606a6df8434948c4552b3cb1176595d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/21666f7af49a90ef44d474916b8ef4402dfd74f5","name":"https://git.kernel.org/stable/c/21666f7af49a90ef44d474916b8ef4402dfd74f5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f5ecaa7ea7686fa7ecdb6affc9d3a9a42e4524b1","name":"https://git.kernel.org/stable/c/f5ecaa7ea7686fa7ecdb6affc9d3a9a42e4524b1","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/828f6670d110ff2bf44c743037b38badc315704c","name":"https://git.kernel.org/stable/c/828f6670d110ff2bf44c743037b38badc315704c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-74550","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74550","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 92d8682926342d2b6aa5b2ecc02221e00e1573a0 f5ecaa7ea7686fa7ecdb6affc9d3a9a42e4524b1 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 92d8682926342d2b6aa5b2ecc02221e00e1573a0 21666f7af49a90ef44d474916b8ef4402dfd74f5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 92d8682926342d2b6aa5b2ecc02221e00e1573a0 5ec5f00fc606a6df8434948c4552b3cb1176595d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 92d8682926342d2b6aa5b2ecc02221e00e1573a0 828f6670d110ff2bf44c743037b38badc315704c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"74550","cve":"CVE-2026-74550","epss":"0.001680000","percentile":"0.065770000","score_date":"2026-08-16","updated_at":"2026-08-17 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the Linux kernel, the following vulnerability has been resolved:\n\nnet: do not send ICMP/NDISC Redirects when peer allocation fails\n\nWhen inet_getpeer_v4() or inet_getpeer_v6() fails to allocate a peer entry\nunder memory pressure or tree size caps, redirect handlers previously fell\nback to sending un-rate-limited ICMP/NDISC Redirect messages.\n\nIn IPv4, ip_rt_send_redirect() called icmp_send() directly when peer == NULL.\nIn IPv6, ip6_forward() and ndisc_send_redirect() passed a NULL peer into\ninet_peer_xrlim_allow(), which returned true when peer == NULL.\n\nBecause ICMP/NDISC Redirects are not part of the default global rate limit\nmask (sysctl_icmp_ratemask), sending redirects when peer == NULL creates\nan un-rate-limited ICMP packet storm.\n\nFix this by failing closed in ip_rt_send_redirect(), ip6_forward(), and\nndisc_send_redirect() when peer is NULL."}],"metrics":[{"cvssV3_1":{"baseScore":7.5,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:N - The flaw is in IPv4/IPv6 packet forwarding paths (ip_forward/ip6_forward) reached when a remote host sends IP traffic processed by a forwarding router; this is standard net stack input handling, not a local-only API.\nAC:L - An attacker can reliably trigger redirect-eligible forwarded packets, flood unique source/destination addresses to stress inet_peer allocation, and induce memory pressure so peer allocation fails, controlling the conditions needed for the un-rate-limited redirect storm.\nPR:N - Exploitation requires only the ability to send IP packets to a forwarding host; no local account, capabilities, or authentication on the victim is needed.\nUI:N - No victim user action is required; the redirect storm is triggered entirely by attacker-sent network packets processed during kernel forwarding.\nS:U - Impact is confined to the kernel/network stack of the targeted forwarding system and its network availability; it does not cross VM, container, or IOMMU security boundaries.\nC:N - The bug bypasses redirect rate limiting to generate ICMP/NDISC storms; it does not involve memory corruption, out-of-bounds access, or unintended disclosure of sensitive kernel memory.\nI:N - The vulnerability causes excessive transmission of otherwise-valid redirect messages; it does not grant arbitrary data modification, code execution, or attacker-controlled corruption of kernel or application state.\nA:H - When peer allocation fails, ICMP/NDISC Redirects are sent without any rate limit (excluded from sysctl_icmp_ratemask), enabling a sustained packet storm that can exhaust CPU, memory, and bandwidth and deny service to the router and adjacent networks."}]}],"providerMetadata":{"dateUpdated":"2026-08-17T05:48:35.407Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/f5ecaa7ea7686fa7ecdb6affc9d3a9a42e4524b1"},{"url":"https://git.kernel.org/stable/c/21666f7af49a90ef44d474916b8ef4402dfd74f5"},{"url":"https://git.kernel.org/stable/c/5ec5f00fc606a6df8434948c4552b3cb1176595d"},{"url":"https://git.kernel.org/stable/c/828f6670d110ff2bf44c743037b38badc315704c"},{"url":"https://git.kernel.org/stable/c/dbc3791e3b2472e1ccc08947e0f83b443470ff4f"}],"title":"net: do not send ICMP/NDISC Redirects when peer allocation 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06:19:52","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"74550","Ordinal":"1","Title":"net: do not send ICMP/NDISC Redirects when peer allocation fails","CVE":"CVE-2026-74550","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"74550","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: do not send ICMP/NDISC Redirects when peer allocation fails\n\nWhen inet_getpeer_v4() or inet_getpeer_v6() fails to allocate a peer entry\nunder memory pressure or tree size caps, redirect handlers previously fell\nback to sending un-rate-limited ICMP/NDISC Redirect messages.\n\nIn IPv4, ip_rt_send_redirect() called icmp_send() directly when peer == NULL.\nIn IPv6, ip6_forward() and ndisc_send_redirect() passed a NULL peer into\ninet_peer_xrlim_allow(), which returned true when peer == NULL.\n\nBecause ICMP/NDISC Redirects are not part of the default global rate limit\nmask (sysctl_icmp_ratemask), sending redirects when peer == NULL creates\nan un-rate-limited ICMP packet storm.\n\nFix this by failing closed in ip_rt_send_redirect(), ip6_forward(), and\nndisc_send_redirect() when peer is NULL.","Type":"Description","Title":"net: do not send ICMP/NDISC Redirects when peer allocation fails"}]}}}