{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-92489","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-16T12:21:13.871Z","datePublished":"2026-09-17T16:10:04.126Z","dateUpdated":"2026-09-18T17:55:28.166Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-18T17:55:28.166Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: Fix skb double-free in xfrm_dev_direct_output()\n\nA return value other than 1 from local_out() means that the skb has been\nconsumed or its ownership was transferred. xfrm_dev_direct_output()\nnevertheless frees the skb on this path, causing a double-free when\nnetfilter drops the packet and invalidating any other owner.\n\nReturn the local_out() result directly, matching the ownership handling\nin xfrm_output_resume()."}],"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 - A received IPv4/IPv6 packet that ip_forward()/ip6_forward() passes through xfrm4_route_forward()/xfrm6_route_forward() reaches xfrm4_output()/xfrm6_output() then xfrm_output(); for an XFRM_DEV_OFFLOAD_PACKET tunnel SA with skb->sk NULL, that forwarded inner IP packet is what xfrm_dev_direct_output() processes.\nAC:L - xfrm_dev_direct_output() calls nf_reset_ct() then dst->ops->local_out (__ip_local_out/__ip6_local_out), so NF_INET_LOCAL_OUT consumes the skb on DROP/QUEUE/STOLEN. The attacker owns the forwarded packet and can force that verdict (iptables/nft DROP, or nf_conntrack_in() NF_DROP when resolve_normal_ct() fails after flooding new 5-tuples); no race is required.\nPR:N - ip_forward() and ip6_forward() take the skb with no socket or credentials; XFRM matching is only the received packet's IP selectors, not an authenticated session. CAP_NET_ADMIN is needed on the victim to install the packet-offload SA, not for the attacker who sends the inner packet.\nUI:N - The attacker triggers the bug only by sending IP packets that an already-configured packet-offload tunnel gateway forwards into xfrm_dev_direct_output(); no victim mount, open, or confirmation is required at exploit time.\nS:U - The sk_buff double-free in xfrm_dev_direct_output() corrupts kernel heap in the same kernel that performs IPsec output and is not a KVM/Xen guest-to-host escape or an IOMMU/DMA boundary bypass.\nC:H - When local_out() returns != 1, nf_hook_slow() has already kfree_skb_reason()'d the skb on NF_DROP (or another owner holds it); the extra kfree_skb() in xfrm_dev_direct_output() is a sk_buff slab double-free that can be reclaimed with crafted packets to read kernel memory.\nI:H - The same sk_buff double-free after __ip_local_out()/__ip6_local_out() transfers ownership lets the attacker reallocate the freed object and obtain a kernel write and control-flow hijack primitive, not a crash-only integrity effect.\nA:H - The extra kfree_skb() in xfrm_dev_direct_output() when local_out() has already consumed the skb corrupts the sk_buff cache and causes a kernel oops or panic."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xfrm/xfrm_output.c"],"versions":[{"version":"bfb9b9404a53a72524ce695551755117e9d3deb0","lessThan":"621871b696b108026bf4b44ed4085ffa2102f417","status":"affected","versionType":"git"},{"version":"a0395e96831adee8ffa016bf958e4dce9ece656e","lessThan":"bc9297796bfdcc8d9609236e54519a4f38737aac","status":"affected","versionType":"git"},{"version":"5eddd76ec2fd1988f0a3450fde9730b10dd22992","lessThan":"02deb637e965950148752a304dd1471212dd6470","status":"affected","versionType":"git"},{"version":"5eddd76ec2fd1988f0a3450fde9730b10dd22992","lessThan":"56a347950e661c1a7f8f31c43a2ea53c2323b6f4","status":"affected","versionType":"git"},{"version":"5eddd76ec2fd1988f0a3450fde9730b10dd22992","lessThan":"2aed51fc58d9ce450e2c116efb956160fd06fa02","status":"affected","versionType":"git"},{"version":"d1d673a5bede3767252cff19c0ab1e5387c6f43f","status":"affected","versionType":"git"},{"version":"6.6.85","lessThan":"6.6.157","status":"affected","versionType":"semver"},{"version":"6.12.21","lessThan":"6.12.110","status":"affected","versionType":"semver"},{"version":"6.13.9","lessThan":"6.14","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xfrm/xfrm_output.c"],"versions":[{"version":"6.14","status":"affected"},{"version":"0","lessThan":"6.14","status":"unaffected","versionType":"semver"},{"version":"6.6.157","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.110","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.52","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.6","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc1","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":"6.6.85","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.21","versionEndExcluding":"6.12.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"6.18.52"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.2.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.3-rc1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13.9"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/621871b696b108026bf4b44ed4085ffa2102f417"},{"url":"https://git.kernel.org/stable/c/bc9297796bfdcc8d9609236e54519a4f38737aac"},{"url":"https://git.kernel.org/stable/c/02deb637e965950148752a304dd1471212dd6470"},{"url":"https://git.kernel.org/stable/c/56a347950e661c1a7f8f31c43a2ea53c2323b6f4"},{"url":"https://git.kernel.org/stable/c/2aed51fc58d9ce450e2c116efb956160fd06fa02"}],"title":"xfrm: Fix skb double-free in xfrm_dev_direct_output()","x_generator":{"engine":"bippy-1.2.0"}}}}