{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72019", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.900Z", "datePublished": "2026-08-15T05:51:46.014Z", "dateUpdated": "2026-08-19T16:35:53.169Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:35:53.169Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmacsec: don't read an unset MAC header in macsec_encrypt()\n\nmacsec_encrypt() reads the Ethernet header via eth_hdr(skb)\n(skb->head + skb->mac_header) to memmove() the 12 source/destination MAC\nbytes forward and make room for the SecTAG.\n\nOn the AF_PACKET SOCK_RAW + PACKET_QDISC_BYPASS transmit path the skb\nreaches the macsec ndo_start_xmit() with the MAC header unset, so\neth_hdr(skb) resolves to skb->head + (u16)~0 and the read is out of\nbounds: a 12-byte heap over-read that is also emitted on the wire as the\nframe's outer source/destination MAC. KASAN reports a slab-out-of-bounds\nread in macsec_start_xmit() on 6.0; on current mainline a CONFIG_DEBUG_NET\nbuild flags it as an unset mac header in skb_mac_header().\n\nOn the TX path the L2 header is at skb->data, so use skb_eth_hdr(), added\nby commit 96cc4b69581d (\"macvlan: do not assume mac_header is set in\nmacvlan_broadcast()\") for exactly this purpose." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H", "baseScore": 7.3, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached only via local AF_PACKET SOCK_RAW transmit with PACKET_QDISC_BYPASS to a macsec netdev; it is a TX-only ndo_start_xmit path, not reachable from remote network packet reception.\nAC:L - An attacker fully controls the trigger: create a raw packet socket with a specific ethertype, enable PACKET_QDISC_BYPASS, and send a frame on a configured macsec interface with protect_frames enabled.\nPR:L - Exploitation requires CAP_NET_RAW for AF_PACKET and CAP_NET_ADMIN to create/configure a macsec netdev and TX SA keys; both are obtainable by an unprivileged user inside a user namespace with delegated capabilities.\nUI:N - No victim interaction is required; the attacker sends crafted frames directly through the vulnerable transmit path without any action from another user or administrator.\nS:U - Impact is confined to kernel heap disclosure and possible kernel crash on the same host; it does not cross a VM, container, or IOMMU security boundary to affect a separate authority.\nC:H - eth_hdr(skb) performs a 12-byte slab out-of-bounds heap read when mac_header is unset; the leaked kernel memory is copied into the transmitted frame's source/destination MAC fields, disclosing sensitive heap contents.\nI:L - The memmove in macsec_encrypt() overwrites the outgoing frame's 12-byte Ethernet addresses with leaked heap data, causing unauthorized modification of transmitted packet contents without arbitrary kernel memory writes.\nA:H - Reading from skb->head plus unset mac_header offset 65535 causes a slab out-of-bounds access that KASAN flags and can page-fault into a kernel oops or panic when macsec_encrypt() runs on affected builds." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/macsec.c" ], "versions": [ { "version": "c09440f7dcb304002dfced8c0fea289eb25f2da0", "lessThan": "b6cec6187b8632423cd99a94fd5e5ba165fa2a33", "status": "affected", "versionType": "git" }, { "version": "c09440f7dcb304002dfced8c0fea289eb25f2da0", "lessThan": "3adea1b1c04b57e08a5c12a1f42483760581ce61", "status": "affected", "versionType": "git" }, { "version": "c09440f7dcb304002dfced8c0fea289eb25f2da0", "lessThan": "dc9ffa1905e72f026d080880a2e4cfc42aa91000", "status": "affected", "versionType": "git" }, { "version": "c09440f7dcb304002dfced8c0fea289eb25f2da0", "lessThan": "f21fa533a3ed15ada74106aac4b9ddd078fc6b7a", "status": "affected", "versionType": "git" }, { "version": "c09440f7dcb304002dfced8c0fea289eb25f2da0", "lessThan": "e17a42199824973cd8212e95b21ffadf4114a21b", "status": "affected", "versionType": "git" }, { "version": "c09440f7dcb304002dfced8c0fea289eb25f2da0", "lessThan": "2cf10d042562283ff4ae97c02d0993d4f1b5ea29", "status": "affected", "versionType": "git" }, { "version": "c09440f7dcb304002dfced8c0fea289eb25f2da0", "lessThan": "c39087ad0b97fc11a3b058dfc8db9fd370762cb9", "status": "affected", "versionType": "git" }, { "version": "c09440f7dcb304002dfced8c0fea289eb25f2da0", "lessThan": "f5089008f90c0a7c5520dff3934e0af00adf322d", "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/macsec.c" ], "versions": [ { "version": "4.6", "status": "affected" }, { "version": "0", "lessThan": "4.6", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.265", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.216", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "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": "4.6", "versionEndExcluding": "5.10.265" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "5.15.216" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/b6cec6187b8632423cd99a94fd5e5ba165fa2a33" }, { "url": "https://git.kernel.org/stable/c/3adea1b1c04b57e08a5c12a1f42483760581ce61" }, { "url": "https://git.kernel.org/stable/c/dc9ffa1905e72f026d080880a2e4cfc42aa91000" }, { "url": "https://git.kernel.org/stable/c/f21fa533a3ed15ada74106aac4b9ddd078fc6b7a" }, { "url": "https://git.kernel.org/stable/c/e17a42199824973cd8212e95b21ffadf4114a21b" }, { "url": "https://git.kernel.org/stable/c/2cf10d042562283ff4ae97c02d0993d4f1b5ea29" }, { "url": "https://git.kernel.org/stable/c/c39087ad0b97fc11a3b058dfc8db9fd370762cb9" }, { "url": "https://git.kernel.org/stable/c/f5089008f90c0a7c5520dff3934e0af00adf322d" } ], "title": "macsec: don't read an unset MAC header in macsec_encrypt()", "x_generator": { "engine": "bippy-1.2.0" } } } }