{"id":"CVE-2026-74473","state":"PUBLISHED","title":"vxlan: use pskb_network_may_pull() in route_shortcircuit()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: use pskb_network_may_pull() in route_shortcircuit()\n\nroute_shortcircuit() currently calls pskb_may_pull(skb, sizeof(struct iphdr))\n(or ipv6hdr), which checks if bytes are available starting from skb->data.\n\nHowever, in vxlan_xmit(), skb->data points to the MAC header, so\nskb_network_offset(skb) is ETH_HLEN (14 bytes). Using pskb_may_pull(skb, 20)\nonly checks 20 bytes from skb->data (which is 14 bytes MAC header + 6 bytes of\nIP header), leaving the rest of the IP header potentially un-pulled in non-linear\nfrags. Subsequent dereferences of ip_hdr(skb)->daddr can read beyond the pulled\nlinear buffer length.\n\nFix this by using pskb_network_may_pull(), which adds skb_network_offset(skb) to\nthe length check to ensure the full network header is present in the linear buffer.","publishedAt":"2026-08-15T12:27:09.382Z","updatedAt":"2026-10-16T19:05:47.966Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/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":"e4f67addf158f98f8197e08974966b18480dc751","status":"affected","lessThan":"c419af4924c1593500a40519730ed98575d04a3e","versionType":"git"},{"version":"e4f67addf158f98f8197e08974966b18480dc751","status":"affected","lessThan":"6bd0a3a1b5744166946f0c551a6665c3b46b05e4","versionType":"git"},{"version":"e4f67addf158f98f8197e08974966b18480dc751","status":"affected","lessThan":"214ba43faf106cb06cd3dd30999c5c809c868b53","versionType":"git"},{"version":"e4f67addf158f98f8197e08974966b18480dc751","status":"affected","lessThan":"42887be7c4cf283cce02cd0fb6411221167c8b6c","versionType":"git"},{"version":"e4f67addf158f98f8197e08974966b18480dc751","status":"affected","lessThan":"aa0d31376d574ac858a40078431a77127bf04ee4","versionType":"git"},{"version":"e4f67addf158f98f8197e08974966b18480dc751","status":"affected","lessThan":"ee799977d7941dbfb11049e17edd9eaf4f8820f7","versionType":"git"},{"version":"e4f67addf158f98f8197e08974966b18480dc751","status":"affected","lessThan":"4f3f96e771a20263635bb5e1307c112d613b4bbd","versionType":"git"},{"version":"e4f67addf158f98f8197e08974966b18480dc751","status":"affected","lessThan":"26bb2dd0a8839617e2c79ffbbe1923f8e4bab9fb","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vxlan/vxlan_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.8","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.151","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.103","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.44","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.8","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vxlan/vxlan_core.c"]}],"references":["https://git.kernel.org/stable/c/c419af4924c1593500a40519730ed98575d04a3e","https://git.kernel.org/stable/c/6bd0a3a1b5744166946f0c551a6665c3b46b05e4","https://git.kernel.org/stable/c/214ba43faf106cb06cd3dd30999c5c809c868b53","https://git.kernel.org/stable/c/42887be7c4cf283cce02cd0fb6411221167c8b6c","https://git.kernel.org/stable/c/aa0d31376d574ac858a40078431a77127bf04ee4","https://git.kernel.org/stable/c/ee799977d7941dbfb11049e17edd9eaf4f8820f7","https://git.kernel.org/stable/c/4f3f96e771a20263635bb5e1307c112d613b4bbd","https://git.kernel.org/stable/c/26bb2dd0a8839617e2c79ffbbe1923f8e4bab9fb"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74473.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74473","state":"PUBLISHED","datePublished":"2026-08-15T12:27:09.382Z","dateUpdated":"2026-10-16T19:05:47.966Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.903Z"},"containers":{"cna":{"title":"vxlan: use pskb_network_may_pull() in route_shortcircuit()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: use pskb_network_may_pull() in route_shortcircuit()\n\nroute_shortcircuit() currently calls pskb_may_pull(skb, sizeof(struct iphdr))\n(or ipv6hdr), which checks if bytes are available starting from skb->data.\n\nHowever, in vxlan_xmit(), skb->data points to the MAC header, so\nskb_network_offset(skb) is ETH_HLEN (14 bytes). Using pskb_may_pull(skb, 20)\nonly checks 20 bytes from skb->data (which is 14 bytes MAC header + 6 bytes of\nIP header), leaving the rest of the IP header potentially un-pulled in non-linear\nfrags. Subsequent dereferences of ip_hdr(skb)->daddr can read beyond the pulled\nlinear buffer length.\n\nFix this by using pskb_network_may_pull(), which adds skb_network_offset(skb) to\nthe length check to ensure the full network header is present in the linear buffer."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e4f67addf158f98f8197e08974966b18480dc751","status":"affected","lessThan":"c419af4924c1593500a40519730ed98575d04a3e","versionType":"git"},{"version":"e4f67addf158f98f8197e08974966b18480dc751","status":"affected","lessThan":"6bd0a3a1b5744166946f0c551a6665c3b46b05e4","versionType":"git"},{"version":"e4f67addf158f98f8197e08974966b18480dc751","status":"affected","lessThan":"214ba43faf106cb06cd3dd30999c5c809c868b53","versionType":"git"},{"version":"e4f67addf158f98f8197e08974966b18480dc751","status":"affected","lessThan":"42887be7c4cf283cce02cd0fb6411221167c8b6c","versionType":"git"},{"version":"e4f67addf158f98f8197e08974966b18480dc751","status":"affected","lessThan":"aa0d31376d574ac858a40078431a77127bf04ee4","versionType":"git"},{"version":"e4f67addf158f98f8197e08974966b18480dc751","status":"affected","lessThan":"ee799977d7941dbfb11049e17edd9eaf4f8820f7","versionType":"git"},{"version":"e4f67addf158f98f8197e08974966b18480dc751","status":"affected","lessThan":"4f3f96e771a20263635bb5e1307c112d613b4bbd","versionType":"git"},{"version":"e4f67addf158f98f8197e08974966b18480dc751","status":"affected","lessThan":"26bb2dd0a8839617e2c79ffbbe1923f8e4bab9fb","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vxlan/vxlan_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.8","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.151","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.103","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.44","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.8","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vxlan/vxlan_core.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/c419af4924c1593500a40519730ed98575d04a3e"},{"url":"https://git.kernel.org/stable/c/6bd0a3a1b5744166946f0c551a6665c3b46b05e4"},{"url":"https://git.kernel.org/stable/c/214ba43faf106cb06cd3dd30999c5c809c868b53"},{"url":"https://git.kernel.org/stable/c/42887be7c4cf283cce02cd0fb6411221167c8b6c"},{"url":"https://git.kernel.org/stable/c/aa0d31376d574ac858a40078431a77127bf04ee4"},{"url":"https://git.kernel.org/stable/c/ee799977d7941dbfb11049e17edd9eaf4f8820f7"},{"url":"https://git.kernel.org/stable/c/4f3f96e771a20263635bb5e1307c112d613b4bbd"},{"url":"https://git.kernel.org/stable/c/26bb2dd0a8839617e2c79ffbbe1923f8e4bab9fb"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - route_shortcircuit() runs in vxlan_xmit() during overlay transmit; remote packets forwarded or routed onto a VXLAN netdev with route-short-circuit enabled reach this path without local access, matching net-stack guidance for network-reachable packet processing on cloud/SDN nodes.\nAC:L - An attacker can reliably craft non-linear skbs (scatter/gather/frags and size boundaries) and aim traffic at a known router MAC in the VXLAN FDB; no race or uncontrollable memory layout is required beyond targeting an RSC-enabled deployment, which is the scored scenario.\nPR:N - Exploitation needs no credentials or capabilities on the victim when VXLAN RSC is already configured; a remote peer only has to send IPv4/IPv6 frames that traverse the tunnel transmit path, with no netlink setup or CAP_NET_ADMIN in the target namespace.\nUI:N - Triggering the bug requires only attacker-controlled network traffic through the overlay; no victim mount, file open, link click, or other interactive action is needed.\nS:U - Impact is confined to the kernel hosting the VXLAN endpoint (memory disclosure, packet-header corruption, or crash); it does not cross VM, container, or IOMMU security boundaries by itself.\nC:H - The faulty pskb_may_pull() check leaves the IP/IPv6 header in non-linear frags, so ip_hdr(skb)->daddr/ipv6 daddr is read past the linear head and can disclose adjacent kernel memory per OOB-read guidance.\nI:H - The out-of-bounds destination address feeds neigh_lookup() and may rewrite eth_hdr()->h_dest before encapsulation, giving attacker-influenced overlay forwarding and a memory-safety primitive in the transmit path.\nA:H - Dereferencing network-header fields beyond the pulled linear buffer can provoke kernel oops/panic on affected skb layouts, and OOB reads in xmit context are treated as high availability impact even when exploitation is not fully weaponized."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-19T16:37:25.639Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"5.10.265"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"5.15.216"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.6.151"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.12.103"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.18.44"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"7.1.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-74473","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T18:57:24.199754Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T19:05:47.966Z"}}]}}}