{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74550", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.915Z", "datePublished": "2026-08-15T12:27:57.615Z", "dateUpdated": "2026-08-19T16:38:44.870Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:38:44.870Z" }, "descriptions": [ { "lang": "en", "value": "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." } ], "metrics": [ { "cvssV3_1": { "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" }, "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." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv4/route.c", "net/ipv6/ip6_output.c", "net/ipv6/ndisc.c" ], "versions": [ { "version": "92d8682926342d2b6aa5b2ecc02221e00e1573a0", "lessThan": "c0adf8b4247bcc5a145a25c1929006eb392580bb", "status": "affected", "versionType": "git" }, { "version": "92d8682926342d2b6aa5b2ecc02221e00e1573a0", "lessThan": "f5ecaa7ea7686fa7ecdb6affc9d3a9a42e4524b1", "status": "affected", "versionType": "git" }, { "version": "92d8682926342d2b6aa5b2ecc02221e00e1573a0", "lessThan": "21666f7af49a90ef44d474916b8ef4402dfd74f5", "status": "affected", "versionType": "git" }, { "version": "92d8682926342d2b6aa5b2ecc02221e00e1573a0", "lessThan": "5ec5f00fc606a6df8434948c4552b3cb1176595d", "status": "affected", "versionType": "git" }, { "version": "92d8682926342d2b6aa5b2ecc02221e00e1573a0", "lessThan": "828f6670d110ff2bf44c743037b38badc315704c", "status": "affected", "versionType": "git" }, { "version": "92d8682926342d2b6aa5b2ecc02221e00e1573a0", "lessThan": "dbc3791e3b2472e1ccc08947e0f83b443470ff4f", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv4/route.c", "net/ipv6/ip6_output.c", "net/ipv6/ndisc.c" ], "versions": [ { "version": "2.6.39", "status": "affected" }, { "version": "0", "lessThan": "2.6.39", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.151", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.103", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.44", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.8", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.39", "versionEndExcluding": "6.1.183" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.39", "versionEndExcluding": "6.6.151" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.39", "versionEndExcluding": "6.12.103" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.39", "versionEndExcluding": "6.18.44" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.39", "versionEndExcluding": "7.1.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.39", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/c0adf8b4247bcc5a145a25c1929006eb392580bb" }, { "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 fails", "x_generator": { "engine": "bippy-1.2.0" } } } }