{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-68476", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.396Z", "datePublished": "2026-08-15T05:51:32.170Z", "dateUpdated": "2026-09-02T12:49:42.932Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-02T12:49:42.932Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipvs: reload ip header after head reallocation\n\n__ip_vs_get_out_rt() calls skb_ensure_writable() which may\nreallocate skb->head." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The flaw is in ip_vs_bypass_xmit() on the IPVS netfilter receive path (NF_INET_LOCAL_IN/FORWARD); remote IPv4 packets to a configured virtual-server VIP reach ip_vs_in_hook() and ip_vs_leave() without local syscalls or ioctl.\nAC:L - Once cache_bypass is enabled on a fwmark IPVS service with no backend, an attacker can repeatedly send traffic to the VIP; cloned skbs (common with bridging, mirroring, or shared receive buffers) make skb_ensure_writable() reallocate skb->head deterministically.\nPR:N - Exploitation requires only sending IP packets to the load balancer VIP; IPVS/cache_bypass configuration is an operator prerequisite on the target, not a Linux capability the remote attacker must hold.\nUI:N - No victim interaction is required; kernel processing of attacker-crafted network packets on the IPVS bypass transmit path alone triggers the stale header pointer use after skb head reallocation.\nS:U - Impact is kernel heap corruption and load-balancer compromise within the host kernel security domain; it does not cross VM, container, or IOMMU boundaries to another security authority.\nC:H - After pskb_expand_head() frees the old skb->head, ip_send_check() uses the stale iph pointer and ip_fast_csum() reads attacker-influenced bytes from freed kmalloc memory, a classic use-after-free information disclosure primitive.\nI:H - ip_send_check() writes through the stale iph pointer (zeroing and updating the checksum field) into freed/reallocated slab memory, enabling heap corruption and potential arbitrary kernel write or control-flow hijack primitives.\nA:H - Writing and reading through a stale IP header pointer after skb head reallocation can corrupt adjacent kernel heap objects or dereference freed memory, causing kernel oops, panic, or hang and repeatable denial of service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/ipvs/ip_vs_xmit.c" ], "versions": [ { "version": "8d8e20e2d7bba8c50e64e0eca1cb83956f468e49", "lessThan": "4f2d1151421520d7ae16ca8d367d0ca09f5dfbd7", "status": "affected", "versionType": "git" }, { "version": "8d8e20e2d7bba8c50e64e0eca1cb83956f468e49", "lessThan": "657118cad620172dfd8f6ed5717fd75c0d1f7a5a", "status": "affected", "versionType": "git" }, { "version": "8d8e20e2d7bba8c50e64e0eca1cb83956f468e49", "lessThan": "a10f5080afbed242640f2984328de25f84557da1", "status": "affected", "versionType": "git" }, { "version": "8d8e20e2d7bba8c50e64e0eca1cb83956f468e49", "lessThan": "ac6ac3d35bfc0ade9d17d354c84e503a946ebdab", "status": "affected", "versionType": "git" }, { "version": "8d8e20e2d7bba8c50e64e0eca1cb83956f468e49", "lessThan": "e51687fc56c2e39ea6e9532925f1aabd4d529f61", "status": "affected", "versionType": "git" }, { "version": "8d8e20e2d7bba8c50e64e0eca1cb83956f468e49", "lessThan": "3fb7edd2018bb1ad0a68157383d9b9dac33dd645", "status": "affected", "versionType": "git" }, { "version": "8d8e20e2d7bba8c50e64e0eca1cb83956f468e49", "lessThan": "ad1e14710b360bda087ebf9fb82460eb5ef775de", "status": "affected", "versionType": "git" }, { "version": "8d8e20e2d7bba8c50e64e0eca1cb83956f468e49", "lessThan": "a2f57827bf7c695b8c72dc4511cae8e86582369d", "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/netfilter/ipvs/ip_vs_xmit.c" ], "versions": [ { "version": "4.10", "status": "affected" }, { "version": "0", "lessThan": "4.10", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.269", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.220", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.187", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "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": "4.10", "versionEndExcluding": "5.10.269" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "5.15.220" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.1.187" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4f2d1151421520d7ae16ca8d367d0ca09f5dfbd7" }, { "url": "https://git.kernel.org/stable/c/657118cad620172dfd8f6ed5717fd75c0d1f7a5a" }, { "url": "https://git.kernel.org/stable/c/a10f5080afbed242640f2984328de25f84557da1" }, { "url": "https://git.kernel.org/stable/c/ac6ac3d35bfc0ade9d17d354c84e503a946ebdab" }, { "url": "https://git.kernel.org/stable/c/e51687fc56c2e39ea6e9532925f1aabd4d529f61" }, { "url": "https://git.kernel.org/stable/c/3fb7edd2018bb1ad0a68157383d9b9dac33dd645" }, { "url": "https://git.kernel.org/stable/c/ad1e14710b360bda087ebf9fb82460eb5ef775de" }, { "url": "https://git.kernel.org/stable/c/a2f57827bf7c695b8c72dc4511cae8e86582369d" } ], "title": "ipvs: reload ip header after head reallocation", "x_generator": { "engine": "bippy-1.2.0" } } } }