{"id":"CVE-2026-72020","title":"ipvs: reset full ip_vs_seq structs in ip_vs_conn_new","summary":"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…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 9a05475cebdd6341884b5901e53870be26e65158 < 3bf9a260188b2a5449cbddc032a749ab433fe328","Linux >= 9a05475cebdd6341884b5901e53870be26e65158 < 6378c5cb360eb1750f88839d7c3613ea92ac1816","Linux >= 9a05475cebdd6341884b5901e53870be26e65158 < 32c299e28b8eea6cbbd23b97dc61401e9ef9c445","Linux >= 9a05475cebdd6341884b5901e53870be26e65158 < 9e36602cbec552286f7e691cfd366525c565ee74","Linux >= 9a05475cebdd6341884b5901e53870be26e65158 < d0eed7177e822cab83141e5c44b2aa345c7fd379","Linux >= 9a05475cebdd6341884b5901e53870be26e65158 < 83fb4c2c5344f02eac929f66de3c9d1adfcde04c","Linux >= 9a05475cebdd6341884b5901e53870be26e65158 < 6335ab62d5fc9ed875279238233fba3462c168f5","Linux >= 9a05475cebdd6341884b5901e53870be26e65158 < 2975324d164c552b028632f107b567302863b7f6","Linux 3.10"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T15:50:08.361059Z"},"published":"2026-08-15","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:53:16.414Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72020","references":[{"url":"https://git.kernel.org/stable/c/3bf9a260188b2a5449cbddc032a749ab433fe328"},{"url":"https://git.kernel.org/stable/c/6378c5cb360eb1750f88839d7c3613ea92ac1816"},{"url":"https://git.kernel.org/stable/c/32c299e28b8eea6cbbd23b97dc61401e9ef9c445"},{"url":"https://git.kernel.org/stable/c/9e36602cbec552286f7e691cfd366525c565ee74"},{"url":"https://git.kernel.org/stable/c/d0eed7177e822cab83141e5c44b2aa345c7fd379"},{"url":"https://git.kernel.org/stable/c/83fb4c2c5344f02eac929f66de3c9d1adfcde04c"},{"url":"https://git.kernel.org/stable/c/6335ab62d5fc9ed875279238233fba3462c168f5"},{"url":"https://git.kernel.org/stable/c/2975324d164c552b028632f107b567302863b7f6"}],"tags":["cve.org"],"epss":0.00714,"epssPercentile":0.52736,"ingestedAt":"2026-10-16T17:24:46.872Z","slug":"CVE-2026-72020","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= 9a05475cebdd6341884b5901e53870be26e65158 < 3bf9a260188b2a5449cbddc032a749ab433fe328`\n- `Linux >= 9a05475cebdd6341884b5901e53870be26e65158 < 6378c5cb360eb1750f88839d7c3613ea92ac1816`\n- `Linux >= 9a05475cebdd6341884b5901e53870be26e65158 < 32c299e28b8eea6cbbd23b97dc61401e9ef9c445`\n- `Linux >= 9a05475cebdd6341884b5901e53870be26e65158 < 9e36602cbec552286f7e691cfd366525c565ee74`\n- `Linux >= 9a05475cebdd6341884b5901e53870be26e65158 < d0eed7177e822cab83141e5c44b2aa345c7fd379`\n- `Linux >= 9a05475cebdd6341884b5901e53870be26e65158 < 83fb4c2c5344f02eac929f66de3c9d1adfcde04c`\n- `Linux >= 9a05475cebdd6341884b5901e53870be26e65158 < 6335ab62d5fc9ed875279238233fba3462c168f5`\n- `Linux >= 9a05475cebdd6341884b5901e53870be26e65158 < 2975324d164c552b028632f107b567302863b7f6`\n- `Linux 3.10`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}