{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74476", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.903Z", "datePublished": "2026-08-15T12:27:11.309Z", "dateUpdated": "2026-08-23T12:47:22.315Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-23T12:47:22.315Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nveth: convert frag_list skbs before running XDP\n\nA frag_list skb can reach veth with data_len set but nr_frags zero.\nveth_convert_skb_to_xdp_buff() only converts skbs that are shared,\nlocked, have frags[], or do not have enough headroom. It later uses\nskb_is_nonlinear() to decide whether to set XDP_FLAGS_HAS_FRAGS and\nxdp_frags_size.\n\nThat exposes frag_list data to XDP as if it were stored in frags[], but\nfrags[] is empty. AF_XDP copy mode can then trust the bogus XDP fragment\nmetadata, walk an empty fragment entry, and crash in memcpy() from\n__xsk_rcv().\n\nRoute non-linear skbs through skb_pp_cow_data() before exposing them to\nXDP, and only advertise XDP frags when the resulting skb has frags[].\nskb_copy_bits() already handles frag_list input, and skb_pp_cow_data()\nbuilds frags[] output with skb_add_rx_frag(), which is the\nrepresentation XDP multi-buffer expects." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H", "baseScore": 9.1, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The bug is hit when a received skb traverses veth XDP processing; in cloud/container deployments (e.g. Cloudflare-style edge nodes) remote traffic routed to a veth peer with XDP+AF_XDP can deliver the malformed frag_list skb without local access.\nAC:L - An attacker can reliably supply the required frag_list skb (data_len>0, nr_frags=0) by transmitting from the veth peer via sockets or GRO aggregation, controlling packet size, timing, and content without depending on uncontrollable kernel state.\nPR:N - Remote exploitation needs no attacker privileges when ingress traffic reaches a veth that already has an XDP program redirecting to an AF_XDP socket; only network-delivered skbs trigger veth_convert_skb_to_xdp_buff() and the faulty __xsk_rcv() path.\nUI:N - No victim user action is required beyond normal network traffic reaching the veth interface; exploitation is automatic once a qualifying frag_list skb is received and redirected to AF_XDP copy mode.\nS:U - The flaw causes kernel memory reads and crashes within the host kernel security boundary; it does not cross VM, hypervisor, or IOMMU isolation boundaries.\nC:H - Bogus XDP_FLAGS_HAS_FRAGS metadata makes __xsk_rcv() memcpy from uninitialized frags[] entries via skb_frag_address(), enabling out-of-bounds kernel memory reads into the AF_XDP receive buffer before faulting.\nI:N - The failure mode is a kernel-side memcpy read using invalid fragment metadata; data is copied into the attacker's AF_XDP ring buffer rather than corrupting kernel or other tenants' memory for integrity purposes.\nA:H - The commit and code path confirm a kernel crash when __xsk_rcv() follows bogus fragment metadata and memcpy faults on an invalid frags[] source address, causing oops/panic and denial of service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/veth.c", "net/core/skbuff.c" ], "versions": [ { "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "0be3632597b8349d43a7dc4244b492dc62a05998", "status": "affected", "versionType": "git" }, { "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "04958dba44dc795dc79ce2fcbc117821bbbd6542", "status": "affected", "versionType": "git" }, { "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "5c1c15c540fc45820ce3033c319151ec891bc10a", "status": "affected", "versionType": "git" }, { "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "b24ba0bbffe3e23eb2f6838881c1fabcb29fb9fb", "status": "affected", "versionType": "git" }, { "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "f9c1fff857e93be709c8b52ed1a643f37bd82c66", "status": "affected", "versionType": "git" }, { "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "d0d6415963040c401e7a7e4e482a698ba52448cb", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/veth.c", "net/core/skbuff.c" ], "versions": [ { "version": "5.18", "status": "affected" }, { "version": "0", "lessThan": "5.18", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.184", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.153", "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": "5.18", "versionEndExcluding": "6.1.184" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.6.153" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.12.103" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.18.44" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "7.1.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/0be3632597b8349d43a7dc4244b492dc62a05998" }, { "url": "https://git.kernel.org/stable/c/04958dba44dc795dc79ce2fcbc117821bbbd6542" }, { "url": "https://git.kernel.org/stable/c/5c1c15c540fc45820ce3033c319151ec891bc10a" }, { "url": "https://git.kernel.org/stable/c/b24ba0bbffe3e23eb2f6838881c1fabcb29fb9fb" }, { "url": "https://git.kernel.org/stable/c/f9c1fff857e93be709c8b52ed1a643f37bd82c66" }, { "url": "https://git.kernel.org/stable/c/d0d6415963040c401e7a7e4e482a698ba52448cb" } ], "title": "veth: convert frag_list skbs before running XDP", "x_generator": { "engine": "bippy-1.2.0" } } } }