{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72351", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.921Z", "datePublished": "2026-08-15T05:55:54.150Z", "dateUpdated": "2026-08-17T05:43:08.849Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:43:08.849Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ngue: validate REMCSUM private option length\n\nGUE private flags can indicate that remote checksum offload metadata is\npresent. The private flags field itself is accounted for by\nguehdr_flags_len(), but guehdr_priv_flags_len() currently returns 0 even\nwhen GUE_PFLAG_REMCSUM is set.\n\nThis lets a packet with only the private flags field pass\nvalidate_gue_flags(), after which gue_remcsum() and gue_gro_remcsum()\nread the missing REMCSUM start/offset fields from the following bytes.\n\nAccount for GUE_PLEN_REMCSUM when GUE_PFLAG_REMCSUM is present so that\nmalformed packets are rejected during option validation." } ], "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 - Malformed GUE-over-UDP packets reach gue_udp_recv() and gue_gro_receive() through the normal IP/UDP receive path on hosts with FOU/GUE listeners, including internet-facing cloud overlay endpoints.\nAC:L - An attacker fully controls the crafted packet and can set GUE_PFLAG_REMCSUM with only the private-flags option present, reliably triggering gue_remcsum()/gue_gro_remcsum() without races or special timing.\nPR:N - Exploitation requires only sending UDP to a GUE listener port; no target credentials or local privileges are needed by the remote attacker even though tunnel setup itself requires admin configuration.\nUI:N - No victim interaction is required beyond the host already receiving GUE tunnel traffic as part of normal overlay networking operation.\nS:U - The flaw corrupts kernel packet buffers during GUE receive processing on the target host and does not inherently cross VM, container, or IOMMU security boundaries.\nC:H - Missing REMCSUM length validation lets attacker-controlled start/offset drive remcsum_adjust()/csum_partial() to read beyond the declared GUE options into adjacent skb bytes, enabling memory disclosure primitives.\nI:H - remcsum_adjust() performs an out-of-bounds 2-byte write at ptr+offset, and the default partial-checksum path stores attacker-controlled csum_start/csum_offset metadata that can corrupt subsequent checksum offload handling.\nA:H - Out-of-bounds REMCSUM processing can trigger kernel oops or panic from invalid memory access or corrupted packet state, causing denial of service on overlay endpoints under repeated attack." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/gue.h" ], "versions": [ { "version": "c1aa8347e73e4092411fbd96cc59531fb7e76d04", "lessThan": "158b9995d3c87f3b93f5c22df54a12e12a3438b3", "status": "affected", "versionType": "git" }, { "version": "c1aa8347e73e4092411fbd96cc59531fb7e76d04", "lessThan": "7c6876ec1b227261b51803f784c7be1b2242a1a0", "status": "affected", "versionType": "git" }, { "version": "c1aa8347e73e4092411fbd96cc59531fb7e76d04", "lessThan": "2c4de9988e9ddc760b750d6b6e701c35ff60ad14", "status": "affected", "versionType": "git" }, { "version": "c1aa8347e73e4092411fbd96cc59531fb7e76d04", "lessThan": "2a99224c120823987e4d829726f4ecb33e03fc1e", "status": "affected", "versionType": "git" }, { "version": "c1aa8347e73e4092411fbd96cc59531fb7e76d04", "lessThan": "61e78679c7c9ca685bff58e4b6348304dc60aafd", "status": "affected", "versionType": "git" }, { "version": "c1aa8347e73e4092411fbd96cc59531fb7e76d04", "lessThan": "4a4a1d41c6e901e773bcf795f562a47fa71f692a", "status": "affected", "versionType": "git" }, { "version": "c1aa8347e73e4092411fbd96cc59531fb7e76d04", "lessThan": "f618cbe9b24cd0202004d2db781d5f80ab77037f", "status": "affected", "versionType": "git" }, { "version": "c1aa8347e73e4092411fbd96cc59531fb7e76d04", "lessThan": "d335dcc6f521571d57117b8deeebc940836e5450", "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/gue.h" ], "versions": [ { "version": "3.19", "status": "affected" }, { "version": "0", "lessThan": "3.19", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.261", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "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": "3.19", "versionEndExcluding": "5.10.261" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/158b9995d3c87f3b93f5c22df54a12e12a3438b3" }, { "url": "https://git.kernel.org/stable/c/7c6876ec1b227261b51803f784c7be1b2242a1a0" }, { "url": "https://git.kernel.org/stable/c/2c4de9988e9ddc760b750d6b6e701c35ff60ad14" }, { "url": "https://git.kernel.org/stable/c/2a99224c120823987e4d829726f4ecb33e03fc1e" }, { "url": "https://git.kernel.org/stable/c/61e78679c7c9ca685bff58e4b6348304dc60aafd" }, { "url": "https://git.kernel.org/stable/c/4a4a1d41c6e901e773bcf795f562a47fa71f692a" }, { "url": "https://git.kernel.org/stable/c/f618cbe9b24cd0202004d2db781d5f80ab77037f" }, { "url": "https://git.kernel.org/stable/c/d335dcc6f521571d57117b8deeebc940836e5450" } ], "title": "gue: validate REMCSUM private option length", "x_generator": { "engine": "bippy-1.2.0" } } } }