{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-53221", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-06-09T07:44:35.392Z", "datePublished": "2026-06-25T08:39:23.177Z", "dateUpdated": "2026-10-19T19:57:29.527Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:34:14.672Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()\n\nIn vti6_tnl_lookup(), when an exact match for a tunnel fails,\nthe code falls back to searching for wildcard tunnels:\n\n- Tunnels matching the packet's local address, with any remote address\n wildcard remote).\n\n- Tunnels matching the packet's remote address, with any local address\n (wildcard local).\n\nHowever, vti6 stores all these different types of tunnels in the same\nhash table (ip6n->tnls_r_l) prone to hash collisions.\n\nThe bug is that the fallback search loops in vti6_tnl_lookup() were\nmissing checks to ensure that the candidate tunnel actually has\na wildcard address." } ], "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 - The vulnerable lookup is reached from IPv6 packet input through registered XFRM ESP/AH/IPComp and IP-in-IPv6 tunnel handlers, so a remote peer can trigger it with network traffic.\nAC:L - The bug is a deterministic missing wildcard-address check in a small hash table; once a plausible VTI6 configuration with colliding wildcard/exact tunnel entries exists, chosen packets reliably exercise the wrong lookup.\nPR:N - The packet receive path reaches `vti6_tnl_lookup()` before any per-packet authentication succeeds, and no local privilege is needed to send the triggering IPv6 traffic.\nUI:N - No victim user action is required; packets are processed by the kernel networking receive path.\nS:U - The impact remains within the kernel/networking security authority and does not by itself cross a VM, IOMMU, or host boundary.\nC:H - Wrong tunnel selection can associate decapsulated traffic with another VTI device, mark, and policy context; in a multi-tenant IPsec/VTI gateway this can expose tunneled plaintext across tunnel boundaries.\nI:H - The same confusion can deliver attacker-controlled inner packets under the wrong tunnel interface and policy context, enabling unauthorized modification or injection of traffic in the affected tunnel domain.\nA:H - Incorrect matching can consistently drop or misprocess traffic for affected tunnels, allowing loss of availability of the VTI/IPsec connectivity in vulnerable configurations." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv6/ip6_vti.c" ], "versions": [ { "version": "fbe68ee87522f6eaa10f9076c0a7117e1613f2f7", "lessThan": "c327fa4fca31415431202e063767a7ae342e19c6", "status": "affected", "versionType": "git" }, { "version": "fbe68ee87522f6eaa10f9076c0a7117e1613f2f7", "lessThan": "fc657ac0767c49839b3ef0b08dc0953ca30883f8", "status": "affected", "versionType": "git" }, { "version": "fbe68ee87522f6eaa10f9076c0a7117e1613f2f7", "lessThan": "47fb3c2b4203556308e64354b3e78f2ce221d646", "status": "affected", "versionType": "git" }, { "version": "fbe68ee87522f6eaa10f9076c0a7117e1613f2f7", "lessThan": "f513f308cc4bdb4530d033431592ffbc29b7fca1", "status": "affected", "versionType": "git" }, { "version": "fbe68ee87522f6eaa10f9076c0a7117e1613f2f7", "lessThan": "90fd4513315ca07da99cfd8549d3e553a7160f0d", "status": "affected", "versionType": "git" }, { "version": "fbe68ee87522f6eaa10f9076c0a7117e1613f2f7", "lessThan": "2abfb19bbb81958714ad1d43ebeb65b30394184b", "status": "affected", "versionType": "git" }, { "version": "fbe68ee87522f6eaa10f9076c0a7117e1613f2f7", "lessThan": "2fc7bc087cc7085368263d9d37bfe9a0bddd6a2d", "status": "affected", "versionType": "git" }, { "version": "fbe68ee87522f6eaa10f9076c0a7117e1613f2f7", "lessThan": "a5c0359f5cbc51a2e2b114d6041e0f3c73f903e9", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv6/ip6_vti.c" ], "versions": [ { "version": "3.19", "status": "affected" }, { "version": "0", "lessThan": "3.19", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.259", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.210", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.176", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.143", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.94", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.36", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.13", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "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": "3.19", "versionEndExcluding": "5.10.259" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "5.15.210" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "6.1.176" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "6.6.143" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "6.12.94" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "6.18.36" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "7.0.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/c327fa4fca31415431202e063767a7ae342e19c6" }, { "url": "https://git.kernel.org/stable/c/fc657ac0767c49839b3ef0b08dc0953ca30883f8" }, { "url": "https://git.kernel.org/stable/c/47fb3c2b4203556308e64354b3e78f2ce221d646" }, { "url": "https://git.kernel.org/stable/c/f513f308cc4bdb4530d033431592ffbc29b7fca1" }, { "url": "https://git.kernel.org/stable/c/90fd4513315ca07da99cfd8549d3e553a7160f0d" }, { "url": "https://git.kernel.org/stable/c/2abfb19bbb81958714ad1d43ebeb65b30394184b" }, { "url": "https://git.kernel.org/stable/c/2fc7bc087cc7085368263d9d37bfe9a0bddd6a2d" }, { "url": "https://git.kernel.org/stable/c/a5c0359f5cbc51a2e2b114d6041e0f3c73f903e9" } ], "title": "ip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-10-15T01:22:46.335Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 TM MFP - GNU/Linux subsystem", "versions": [ { "status": "affected", "version": "0", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" } ], "references": [ { "url": "https://cert-portal.siemens.com/productcert/html/ssa-784472.html" } ] }, { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-53221", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T15:27:05.371871Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-20", "description": "CWE-20 Improper Input Validation" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-19T19:57:29.527Z" } } ] } }