{"id":"CVE-2026-72020","revision":"2d8e150a5cf1454697f4127e0072c1a0","records":[{"revision":"2d8e150a5cf1454697f4127e0072c1a0","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-72020","aliases":[],"title":"ipvs: reset full ip_vs_seq structs in ip_vs_conn_new","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipvs: reset full ip_vs_seq structs in ip_vs_conn_new\n\nCommit 9a05475cebdd (\"ipvs: avoid kmem_cache_zalloc in\nip_vs_conn_new\") changed ip_vs_conn_new() to allocate an ip_vs_conn\nobject with kmem_cache_alloc().  The function then initializes many\nfields explicitly, but only resets in_seq.delta and out_seq.delta in the\ntwo struct ip_vs_seq members.\n\nThat leaves init_seq and previous_delta uninitialized.  This is normally\nharmless while the corresponding IP_VS_CONN_F_IN_SEQ or\nIP_VS_CONN_F_OUT_SEQ flag is clear.  For connections learned from a sync\nmessage, however, ip_vs_proc_conn() preserves those flags from\nIP_VS_CONN_F_BACKUP_MASK and passes opt=NULL when the message omits\nIPVS_OPT_SEQ_DATA.  In that case the new connection can be hashed with\nSEQ flags set but with the rest of in_seq/out_seq still containing stale\nslab data.\n\nWhen a packet for such a connection is later handled by an IPVS\napplication helper, vs_fix_seq() and vs_fix_ack_seq() use\nprevious_delta and init_seq to rewrite TCP sequence numbers.  A malformed\nsync message can therefore make forwarded packets carry stale slab bytes\nin their TCP seq/ack numbers, and can also corrupt the forwarded TCP\nflow.\n\nReset both struct ip_vs_seq members completely before publishing the\nconnection.  This matches the existing \"reset struct ip_vs_seq\" comment\nand keeps the sequence-adjustment gates inactive unless valid sequence\ndata is installed later.","state":0,"publishedAt":"2026-08-15T05:51:46.675+00:00","modifiedAt":"2026-10-19T21:19:23.243+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/netfilter/ipvs/ip_vs_conn.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"9a05475cebdd6341884b5901e53870be26e65158\",\n                            \"lessThan\": \"3bf9a260188b2a5449cbddc032a749ab433fe328\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9a05475cebdd6341884b5901e53870be26e65158\",\n                            \"lessThan\": \"6378c5cb360eb1750f88839d7c3613ea92ac1816\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9a05475cebdd6341884b5901e53870be26e65158\",\n                            \"lessThan\": \"32c299e28b8eea6cbbd23b97dc61401e9ef9c445\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9a05475cebdd6341884b5901e53870be26e65158\",\n                            \"lessThan\": \"9e36602cbec552286f7e691cfd366525c565ee74\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9a05475cebdd6341884b5901e53870be26e65158\",\n                            \"lessThan\": \"d0eed7177e822cab83141e5c44b2aa345c7fd379\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9a05475cebdd6341884b5901e53870be26e65158\",\n                            \"lessThan\": \"83fb4c2c5344f02eac929f66de3c9d1adfcde04c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9a05475cebdd6341884b5901e53870be26e65158\",\n                            \"lessThan\": \"6335ab62d5fc9ed875279238233fba3462c168f5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9a05475cebdd6341884b5901e53870be26e65158\",\n                            \"lessThan\": \"2975324d164c552b028632f107b567302863b7f6\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/netfilter/ipvs/ip_vs_conn.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"3.10\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"3.10\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.261\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.212\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.178\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.145\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.97\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.40\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.5\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8,"severity":"CRITICAL"}],"references":["https://git.kernel.org/stable/c/3bf9a260188b2a5449cbddc032a749ab433fe328","https://git.kernel.org/stable/c/6378c5cb360eb1750f88839d7c3613ea92ac1816","https://git.kernel.org/stable/c/32c299e28b8eea6cbbd23b97dc61401e9ef9c445","https://git.kernel.org/stable/c/9e36602cbec552286f7e691cfd366525c565ee74","https://git.kernel.org/stable/c/d0eed7177e822cab83141e5c44b2aa345c7fd379","https://git.kernel.org/stable/c/83fb4c2c5344f02eac929f66de3c9d1adfcde04c","https://git.kernel.org/stable/c/6335ab62d5fc9ed875279238233fba3462c168f5","https://git.kernel.org/stable/c/2975324d164c552b028632f107b567302863b7f6"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72020","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-72020","identifiers":["CVE-2026-72020"]},"retained":false,"historicalAffected":[]}],"coverage":[]}