{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74724","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-15T05:44:03.929Z","datePublished":"2026-08-22T15:33:15.832Z","dateUpdated":"2026-08-25T05:42:04.705Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-25T05:42:04.705Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nipvs: avoid out-of-bounds write in ip_vs_nat_icmp\n\nSashiko warns that local attacker can modify the packet\nwhile it is processed by IPVS. Some places read the\nIP ihl field multiple times which can cause out-of-bounds\naccess. One such place is ip_vs_nat_icmp where we\ncan write after the validated area.\n\nFix it by providing ciph argument just like it is done for\nIPv6 and use ciph->len as offset to the embedded transport\nheader.\n\nModify some IPv4 header checks by reading the ihl field\nonly once."}],"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 OOB write in ip_vs_nat_icmp() requires a local process to change the embedded IPv4 ihl in skb frags between ip_vs_fill_iph_skb_icmp() validation and the NAT write; remote-only ICMP to IPVS netfilter hooks cannot perform that TOCTOU without local access to the packet buffer.\nAC:L - A local attacker controls both sides of the race by concurrently injecting ICMP errors with TCP/UDP/SCTP payloads matching an IPVS NAT connection and modifying the embedded header ihl in skb frags during softirq processing; no victim-specific state or uncontrollable heap layout is required.\nPR:L - Triggering requires a local account able to race skb frag modification (e.g., via raw/packet sockets with CAP_NET_RAW, obtainable in a user namespace) against IPVS ICMP NAT handling on a host where IPVS is already configured; no init-namespace root is needed.\nUI:N - No victim user interaction is required; exploitation is driven entirely by attacker-controlled local packet injection and concurrent frag modification while IPVS processes ICMP errors on NAT-mode connections through LOCAL_IN, LOCAL_OUT, or FORWARD hooks.\nS:U - The out-of-bounds write corrupts kernel skb memory on the IPVS load-balancer host within the same kernel security authority; it does not cross VM, container, or IOMMU boundaries into a separate security scope.\nC:H - Writing TCP/UDP/SCTP port fields and running ip_send_check() using a re-read inflated ihl corrupts skb data beyond the validated region; out-of-bounds kernel memory corruption is exploitable for information disclosure and heap layout control.\nI:H - The bug is an out-of-bounds write of 16-bit port values (and checksum updates over an attacker-inflated header length) past skb_ensure_writable()'s bound, enabling adjacent kernel memory corruption and potential control-flow hijacking on internet-facing IPVS NAT nodes.\nA:H - Corrupting skb header memory beyond the ensured writable area can cause kernel oops or panic during ICMP NAT mangling; a local attacker can repeatedly trigger the race on kube-proxy IPVS nodes and hardware load balancers running IPVS NAT mode."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/ip_vs.h","net/netfilter/ipvs/ip_vs_core.c","net/netfilter/ipvs/ip_vs_xmit.c"],"versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"3b8f79af0e98f27b932b0b416e9c52b692d31ff9","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"3c779b258c9c3c3567af68d4f45c2f751f35bd0e","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"be65fa324640c7a95e30b146159a2be5cc73f22e","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"a69a4b3fff5814d079beff9a1e9d369994b2ed47","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"243d0187ec4c3837b9b0004f18d1068e46115760","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"646922a0379496154e8c8faca4f8e2fd9100cacc","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/ip_vs.h","net/netfilter/ipvs/ip_vs_core.c","net/netfilter/ipvs/ip_vs_xmit.c"],"versions":[{"version":"2.6.12","status":"affected"},{"version":"0","lessThan":"2.6.12","status":"unaffected","versionType":"semver"},{"version":"6.1.183","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":"2.6.12","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.6.152"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.12.104"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.18.45"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.1.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/3b8f79af0e98f27b932b0b416e9c52b692d31ff9"},{"url":"https://git.kernel.org/stable/c/3c779b258c9c3c3567af68d4f45c2f751f35bd0e"},{"url":"https://git.kernel.org/stable/c/be65fa324640c7a95e30b146159a2be5cc73f22e"},{"url":"https://git.kernel.org/stable/c/a69a4b3fff5814d079beff9a1e9d369994b2ed47"},{"url":"https://git.kernel.org/stable/c/243d0187ec4c3837b9b0004f18d1068e46115760"},{"url":"https://git.kernel.org/stable/c/646922a0379496154e8c8faca4f8e2fd9100cacc"}],"title":"ipvs: avoid out-of-bounds write in ip_vs_nat_icmp","x_generator":{"engine":"bippy-1.2.0"}}}}