{ "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": "2026-10-19T09:03:55.784Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:03:55.784Z" }, "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", "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" }, { "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" } } } }