{"id":"CVE-2026-22988","state":"PUBLISHED","title":"arp: do not assume dev_hard_header() does not change skb->head","description":"In the Linux kernel, the following vulnerability has been resolved:\n\narp: do not assume dev_hard_header() does not change skb->head\n\narp_create() is the only dev_hard_header() caller\nmaking assumption about skb->head being unchanged.\n\nA recent commit broke this assumption.\n\nInitialize @arp pointer after dev_hard_header() call.","publishedAt":"2026-01-23T15:24:09.756Z","updatedAt":"2026-08-05T12:19:56.911Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"17e7386234f740f3e7d5e58a47b5847ea34c3bc2","status":"affected","lessThan":"e432dbff342b95fe44645f9a90fcf333c80f4b5e","versionType":"git"},{"version":"41a1a3140aff295dee8063906f70a514548105e8","status":"affected","lessThan":"393525dee5c39acff8d6705275d7fcaabcfb7f0a","versionType":"git"},{"version":"adee129db814474f2f81207bd182bf343832a52e","status":"affected","lessThan":"70bddc16491ef4681f3569b3a2c80309a3edcdd1","versionType":"git"},{"version":"1717357007db150c2d703f13f5695460e960f26c","status":"affected","lessThan":"029935507d0af6553c45380fbf6feecf756fd226","versionType":"git"},{"version":"5fe210533e3459197eabfdbf97327dacbdc04d60","status":"affected","lessThan":"dd6ccec088adff4bdf33e2b2dd102df20a7128fa","versionType":"git"},{"version":"91a2b25be07ce1a7549ceebbe82017551d2eec92","status":"affected","lessThan":"949647e7771a4a01963fe953a96d81fba7acecf3","versionType":"git"},{"version":"db5b4e39c4e63700c68a7e65fc4e1f1375273476","status":"affected","lessThan":"c92510f5e3f82ba11c95991824a41e59a9c5ed81","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/arp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"6.1.160","status":"affected","lessThan":"6.1.161","versionType":"semver"},{"version":"6.6.120","status":"affected","lessThan":"6.6.121","versionType":"semver"},{"version":"6.12.64","status":"affected","lessThan":"6.12.66","versionType":"semver"},{"version":"6.18.4","status":"affected","lessThan":"6.18.6","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/arp.c"]}],"references":["https://git.kernel.org/stable/c/e432dbff342b95fe44645f9a90fcf333c80f4b5e","https://git.kernel.org/stable/c/393525dee5c39acff8d6705275d7fcaabcfb7f0a","https://git.kernel.org/stable/c/70bddc16491ef4681f3569b3a2c80309a3edcdd1","https://git.kernel.org/stable/c/029935507d0af6553c45380fbf6feecf756fd226","https://git.kernel.org/stable/c/dd6ccec088adff4bdf33e2b2dd102df20a7128fa","https://git.kernel.org/stable/c/949647e7771a4a01963fe953a96d81fba7acecf3","https://git.kernel.org/stable/c/c92510f5e3f82ba11c95991824a41e59a9c5ed81"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:21.040Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/22xxx/CVE-2026-22988.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-22988","state":"PUBLISHED","datePublished":"2026-01-23T15:24:09.756Z","dateUpdated":"2026-08-05T12:19:56.911Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-01-13T15:37:45.937Z"},"containers":{"cna":{"title":"arp: do not assume dev_hard_header() does not change skb->head","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\narp: do not assume dev_hard_header() does not change skb->head\n\narp_create() is the only dev_hard_header() caller\nmaking assumption about skb->head being unchanged.\n\nA recent commit broke this assumption.\n\nInitialize @arp pointer after dev_hard_header() call."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"17e7386234f740f3e7d5e58a47b5847ea34c3bc2","status":"affected","lessThan":"e432dbff342b95fe44645f9a90fcf333c80f4b5e","versionType":"git"},{"version":"41a1a3140aff295dee8063906f70a514548105e8","status":"affected","lessThan":"393525dee5c39acff8d6705275d7fcaabcfb7f0a","versionType":"git"},{"version":"adee129db814474f2f81207bd182bf343832a52e","status":"affected","lessThan":"70bddc16491ef4681f3569b3a2c80309a3edcdd1","versionType":"git"},{"version":"1717357007db150c2d703f13f5695460e960f26c","status":"affected","lessThan":"029935507d0af6553c45380fbf6feecf756fd226","versionType":"git"},{"version":"5fe210533e3459197eabfdbf97327dacbdc04d60","status":"affected","lessThan":"dd6ccec088adff4bdf33e2b2dd102df20a7128fa","versionType":"git"},{"version":"91a2b25be07ce1a7549ceebbe82017551d2eec92","status":"affected","lessThan":"949647e7771a4a01963fe953a96d81fba7acecf3","versionType":"git"},{"version":"db5b4e39c4e63700c68a7e65fc4e1f1375273476","status":"affected","lessThan":"c92510f5e3f82ba11c95991824a41e59a9c5ed81","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/arp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"6.1.160","status":"affected","lessThan":"6.1.161","versionType":"semver"},{"version":"6.6.120","status":"affected","lessThan":"6.6.121","versionType":"semver"},{"version":"6.12.64","status":"affected","lessThan":"6.12.66","versionType":"semver"},{"version":"6.18.4","status":"affected","lessThan":"6.18.6","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/arp.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/e432dbff342b95fe44645f9a90fcf333c80f4b5e"},{"url":"https://git.kernel.org/stable/c/393525dee5c39acff8d6705275d7fcaabcfb7f0a"},{"url":"https://git.kernel.org/stable/c/70bddc16491ef4681f3569b3a2c80309a3edcdd1"},{"url":"https://git.kernel.org/stable/c/029935507d0af6553c45380fbf6feecf756fd226"},{"url":"https://git.kernel.org/stable/c/dd6ccec088adff4bdf33e2b2dd102df20a7128fa"},{"url":"https://git.kernel.org/stable/c/949647e7771a4a01963fe953a96d81fba7acecf3"},{"url":"https://git.kernel.org/stable/c/c92510f5e3f82ba11c95991824a41e59a9c5ed81"}],"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 demonstrated trigger path is a local rtnetlink sendmsg that changes network device state and causes gratuitous ARP generation through arp_create(). Remote ARP paths can call arp_create(), but the UAF condition depends on locally controlled virtual device/headroom state such as ip6gre stacking.\nAC:L - Once the affected device configuration is present, triggering arp_create() and the ip6gre_header() head expansion is straightforward. Any needed setup or race is controlled by the local attacker through netlink operations.\nPR:L - The relevant rtnetlink operations require CAP_NET_ADMIN in the target network namespace. This is low privilege because an unprivileged local user can obtain CAP_NET_ADMIN in a new user/network namespace on systems with user namespaces enabled.\nUI:N - No victim action is required after the attacker performs the local network configuration and trigger operation. The vulnerable path runs in kernel networking code.\nS:U - The corruption occurs within the kernel networking subsystem and impacts the same kernel security authority. It does not cross a VM, IOMMU, or other separate security boundary.\nC:H - The bug is a slab use-after-free write after pskb_expand_head() moves skb->head, leaving arp_create() writing through a stale pointer. Kernel UAF memory corruption can be leveraged for information disclosure, so confidentiality impact is high.\nI:H - The stale ARP header pointer is used for attacker-influenced writes into freed kernel heap memory. This is memory corruption with plausible control-flow or object corruption exploitation, so integrity impact is high.\nA:H - KASAN reports confirm a slab-use-after-free write in arp_create(), and such corruption can directly crash or panic the kernel. Repeated triggering can cause system-wide denial of service."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:19:56.911Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.160","versionEndExcluding":"6.1.161"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.120","versionEndExcluding":"6.6.121"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.64","versionEndExcluding":"6.12.66"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18.4","versionEndExcluding":"6.18.6"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}