{"apiVersion":"1.0","identifier":"CVE-2026-74582","description":"In the Linux kernel, the following vulnerability has been resolved: packet: use consistent hard_header_len in non-ring send paths packet_snd() reads dev->hard_header_len multiple times while allocating and constructing an skb. Device reconfiguration can change this value concurrently, for example through bonding device type changes. For SOCK_RAW, packet_snd() can save a larger value in reserve and later allocate headroom using a smaller value. Moving skb->data back by reserve then places it before skb->head, and the following copy from userspace can attempt an out-of-bounds write. packet_sendmsg_spkt() has the same issue because it calculates its reservation and header offset from separate reads before dropping the RCU read lock to allocate the skb. Add LL_RESERVED_SPACE_EX() for callers that already saved a header length. Read hard_header_len once in packet_snd() and use it for allocation and construction. In packet_sendmsg_spkt(), preserve the allocation-time value through the device lookup retry. The separate SOCK_DGRAM consistency problem between hard_header_len and header_ops->create is not addressed here.","publishedAt":"2026-08-21T17:16:44","lastModifiedAt":"2026-08-27T13:18:34","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74582","cvssScore":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","epssProbability":0.0012,"riskScore":0.79,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-74582","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-74582","en":"https://www.redsauce.net/en/cves/CVE-2026-74582","fr":"https://www.redsauce.net/fr/cves/CVE-2026-74582","pt":"https://www.redsauce.net/pt/cves/CVE-2026-74582","de":"https://www.redsauce.net/de/cves/CVE-2026-74582","sk":"https://www.redsauce.net/sk/cves/CVE-2026-74582","el":"https://www.redsauce.net/el/cves/CVE-2026-74582"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-74582"}}