{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74582", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.918Z", "datePublished": "2026-08-21T16:31:55.283Z", "dateUpdated": "2026-10-16T19:05:58.230Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-27T12:39:47.499Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npacket: use consistent hard_header_len in non-ring send paths\n\npacket_snd() reads dev->hard_header_len multiple times while allocating\nand constructing an skb. Device reconfiguration can change this value\nconcurrently, for example through bonding device type changes.\n\nFor SOCK_RAW, packet_snd() can save a larger value in reserve and later\nallocate headroom using a smaller value. Moving skb->data back by reserve\nthen places it before skb->head, and the following copy from userspace can\nattempt an out-of-bounds write.\n\npacket_sendmsg_spkt() has the same issue because it calculates its\nreservation and header offset from separate reads before dropping the RCU\nread lock to allocate the skb.\n\nAdd LL_RESERVED_SPACE_EX() for callers that already saved a header length.\nRead hard_header_len once in packet_snd() and use it for allocation and\nconstruction. In packet_sendmsg_spkt(), preserve the allocation-time value\nthrough the device lookup retry.\n\nThe separate SOCK_DGRAM consistency problem between hard_header_len and\nheader_ops->create is not addressed here." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The flaw is in packet_snd() and packet_sendmsg_spkt() on the local AF_PACKET sendmsg() transmit path; it is not triggered by processing remotely received network traffic or pre-authentication network services.\nAC:L - An attacker in a user+network namespace can open an AF_PACKET SOCK_RAW socket and concurrently reconfigure the bound netdev (bonding/VLAN/macvlan/team) to change hard_header_len, controlling both sides of the race without external timing.\nPR:L - Exploitation requires CAP_NET_RAW to create AF_PACKET sockets and CAP_NET_ADMIN to change netdev hard_header_len; both are obtainable by an unprivileged user inside a user namespace without init-namespace root.\nUI:N - No victim interaction is required; the attacker triggers the bug using their own packet socket sendmsg calls and concurrent netdev reconfiguration threads.\nS:U - Impact is kernel heap corruption and local privilege escalation within the same kernel security domain; it does not constitute a VM escape, sandbox breakout, or IOMMU boundary bypass.\nC:H - Racing hard_header_len can place skb->data before skb->head, and skb_copy_datagram_from_iter/memcpy_from_msg then writes attacker-controlled data outside the skb buffer, corrupting adjacent slab objects and enabling kernel memory disclosure.\nI:H - Inconsistent hard_header_len between skb allocation and header adjustment causes out-of-bounds kernel heap writes of attacker-controlled packet data, yielding corruption primitives suitable for control-flow hijacking and local privilege escalation.\nA:H - Out-of-bounds skb buffer writes corrupt kmalloc metadata and can trigger kernel oops/panic, causing reliable denial of service even when full exploitation is not completed." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/linux/netdevice.h", "net/packet/af_packet.c" ], "versions": [ { "version": "b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba", "lessThan": "bcd4df60ac9481b1ceffdfe5ec38fe51dcaae812", "status": "affected", "versionType": "git" }, { "version": "b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba", "lessThan": "78a47127e33c340bc6d38dcc4552a094b4f5cc77", "status": "affected", "versionType": "git" }, { "version": "b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba", "lessThan": "142e287b3a25cfe909215177c23243e7fc5ae2b1", "status": "affected", "versionType": "git" }, { "version": "b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba", "lessThan": "91f041451f967cd87ed722a8f43c0b767a64f1a0", "status": "affected", "versionType": "git" }, { "version": "b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba", "lessThan": "9052756290962ffb9a661bcf319e92dedaaedfed", "status": "affected", "versionType": "git" }, { "version": "b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba", "lessThan": "5bb10753d428aadfc356a2bfe9acea09c82a62ec", "status": "affected", "versionType": "git" }, { "version": "b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba", "lessThan": "b06b6fce6d7deaf7238e09b48ce3b1125ff41acd", "status": "affected", "versionType": "git" }, { "version": "b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba", "lessThan": "03390aa32e669cc4ecd7d34108e2e1afc13d689d", "status": "affected", "versionType": "git" }, { "version": "d9fb8cc230b2a4757e9fe4f81468f81212d4deaa", "status": "affected", "versionType": "git" }, { "version": "6190cce26e40bf71c4d375b21eea74bb07b6a0f3", "status": "affected", "versionType": "git" }, { "version": "01a658c1b9d4b5393c38d5a92d9112ab1425382a", "status": "affected", "versionType": "git" }, { "version": "8809ae6747e760e6f1d2453ceb08c9bcc4939766", "status": "affected", "versionType": "git" }, { "version": "4.4.133", "lessThan": "4.5", "status": "affected", "versionType": "semver" }, { "version": "4.9.103", "lessThan": "4.10", "status": "affected", "versionType": "semver" }, { "version": "4.14.44", "lessThan": "4.15", "status": "affected", "versionType": "semver" }, { "version": "4.16.12", "lessThan": "4.17", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/linux/netdevice.h", "net/packet/af_packet.c" ], "versions": [ { "version": "4.17", "status": "affected" }, { "version": "0", "lessThan": "4.17", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.267", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.218", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.185", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.152", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.104", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.45", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.9", "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": "4.17", "versionEndExcluding": "5.10.267" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "5.15.218" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.1.185" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.6.152" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.12.104" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.18.45" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "7.1.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4.133" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9.103" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14.44" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16.12" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/bcd4df60ac9481b1ceffdfe5ec38fe51dcaae812" }, { "url": "https://git.kernel.org/stable/c/78a47127e33c340bc6d38dcc4552a094b4f5cc77" }, { "url": "https://git.kernel.org/stable/c/142e287b3a25cfe909215177c23243e7fc5ae2b1" }, { "url": "https://git.kernel.org/stable/c/91f041451f967cd87ed722a8f43c0b767a64f1a0" }, { "url": "https://git.kernel.org/stable/c/9052756290962ffb9a661bcf319e92dedaaedfed" }, { "url": "https://git.kernel.org/stable/c/5bb10753d428aadfc356a2bfe9acea09c82a62ec" }, { "url": "https://git.kernel.org/stable/c/b06b6fce6d7deaf7238e09b48ce3b1125ff41acd" }, { "url": "https://git.kernel.org/stable/c/03390aa32e669cc4ecd7d34108e2e1afc13d689d" } ], "title": "packet: use consistent hard_header_len in non-ring send paths", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-74582", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:01:14.406882Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:05:58.230Z" } } ] } }