CVE-2026-72020 - Vulnerability Details

Vendors	Products
Linux	Linux Kernel

Link	Providers
https://git.kernel.org/stable/c/2975324d164c552b028632f107b567302863b7f6
https://git.kernel.org/stable/c/32c299e28b8eea6cbbd23b97dc61401e9ef9c445
https://git.kernel.org/stable/c/3bf9a260188b2a5449cbddc032a749ab433fe328
https://git.kernel.org/stable/c/6335ab62d5fc9ed875279238233fba3462c168f5
https://git.kernel.org/stable/c/6378c5cb360eb1750f88839d7c3613ea92ac1816
https://git.kernel.org/stable/c/83fb4c2c5344f02eac929f66de3c9d1adfcde04c
https://git.kernel.org/stable/c/9e36602cbec552286f7e691cfd366525c565ee74
https://git.kernel.org/stable/c/d0eed7177e822cab83141e5c44b2aa345c7fd379

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: ipvs: reset full ip_vs_seq structs in ip_vs_conn_new Commit 9a05475cebdd ("ipvs: avoid kmem_cache_zalloc in ip_vs_conn_new") changed ip_vs_conn_new() to allocate an ip_vs_conn object with kmem_cache_alloc(). The function then initializes many fields explicitly, but only resets in_seq.delta and out_seq.delta in the two struct ip_vs_seq members. That leaves init_seq and previous_delta uninitialized. This is normally harmless while the corresponding IP_VS_CONN_F_IN_SEQ or IP_VS_CONN_F_OUT_SEQ flag is clear. For connections learned from a sync message, however, ip_vs_proc_conn() preserves those flags from IP_VS_CONN_F_BACKUP_MASK and passes opt=NULL when the message omits IPVS_OPT_SEQ_DATA. In that case the new connection can be hashed with SEQ flags set but with the rest of in_seq/out_seq still containing stale slab data. When a packet for such a connection is later handled by an IPVS application helper, vs_fix_seq() and vs_fix_ack_seq() use previous_delta and init_seq to rewrite TCP sequence numbers. A malformed sync message can therefore make forwarded packets carry stale slab bytes in their TCP seq/ack numbers, and can also corrupt the forwarded TCP flow. Reset both struct ip_vs_seq members completely before publishing the connection. This matches the existing "reset struct ip_vs_seq" comment and keeps the sequence-adjustment gates inactive unless valid sequence data is installed later.
Title		ipvs: reset full ip_vs_seq structs in ip_vs_conn_new
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/2975324d164c552b028632f107b567302863b7f6 https://git.kernel.org/stable/c/32c299e28b8eea6cbbd23b97dc61401e9ef9c445 https://git.kernel.org/stable/c/3bf9a260188b2a5449cbddc032a749ab433fe328 https://git.kernel.org/stable/c/6335ab62d5fc9ed875279238233fba3462c168f5 https://git.kernel.org/stable/c/6378c5cb360eb1750f88839d7c3613ea92ac1816 https://git.kernel.org/stable/c/83fb4c2c5344f02eac929f66de3c9d1adfcde04c https://git.kernel.org/stable/c/9e36602cbec552286f7e691cfd366525c565ee74 https://git.kernel.org/stable/c/d0eed7177e822cab83141e5c44b2aa345c7fd379

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-72020", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.900Z", "datePublished": "2026-08-15T05:51:46.675Z", "dateUpdated": "2026-08-15T05:51:46.675Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-15T05:51:46.675Z"}, "descriptions": [{"lang": "en", "value": "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."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/netfilter/ipvs/ip_vs_conn.c"], "versions": [{"version": "9a05475cebdd6341884b5901e53870be26e65158", "lessThan": "3bf9a260188b2a5449cbddc032a749ab433fe328", "status": "affected", "versionType": "git"}, {"version": "9a05475cebdd6341884b5901e53870be26e65158", "lessThan": "6378c5cb360eb1750f88839d7c3613ea92ac1816", "status": "affected", "versionType": "git"}, {"version": "9a05475cebdd6341884b5901e53870be26e65158", "lessThan": "32c299e28b8eea6cbbd23b97dc61401e9ef9c445", "status": "affected", "versionType": "git"}, {"version": "9a05475cebdd6341884b5901e53870be26e65158", "lessThan": "9e36602cbec552286f7e691cfd366525c565ee74", "status": "affected", "versionType": "git"}, {"version": "9a05475cebdd6341884b5901e53870be26e65158", "lessThan": "d0eed7177e822cab83141e5c44b2aa345c7fd379", "status": "affected", "versionType": "git"}, {"version": "9a05475cebdd6341884b5901e53870be26e65158", "lessThan": "83fb4c2c5344f02eac929f66de3c9d1adfcde04c", "status": "affected", "versionType": "git"}, {"version": "9a05475cebdd6341884b5901e53870be26e65158", "lessThan": "6335ab62d5fc9ed875279238233fba3462c168f5", "status": "affected", "versionType": "git"}, {"version": "9a05475cebdd6341884b5901e53870be26e65158", "lessThan": "2975324d164c552b028632f107b567302863b7f6", "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/netfilter/ipvs/ip_vs_conn.c"], "versions": [{"version": "3.10", "status": "affected"}, {"version": "0", "lessThan": "3.10", "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-rc3", "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": "3.10", "versionEndExcluding": "5.10.261"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "5.15.212"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "6.1.178"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "6.6.145"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "6.12.97"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "6.18.40"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "7.1.5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "7.2-rc3"}]}]}], "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"}], "title": "ipvs: reset full ip_vs_seq structs in ip_vs_conn_new", "x_generator": {"engine": "bippy-1.2.0"}}}}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/netfilter/ipvs/ip_vs_conn.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "3bf9a260188b2a5449cbddc032a749ab433fe328", "status": "affected", "version": "9a05475cebdd6341884b5901e53870be26e65158", "versionType": "git"}, {"lessThan": "6378c5cb360eb1750f88839d7c3613ea92ac1816", "status": "affected", "version": "9a05475cebdd6341884b5901e53870be26e65158", "versionType": "git"}, {"lessThan": "32c299e28b8eea6cbbd23b97dc61401e9ef9c445", "status": "affected", "version": "9a05475cebdd6341884b5901e53870be26e65158", "versionType": "git"}, {"lessThan": "9e36602cbec552286f7e691cfd366525c565ee74", "status": "affected", "version": "9a05475cebdd6341884b5901e53870be26e65158", "versionType": "git"}, {"lessThan": "d0eed7177e822cab83141e5c44b2aa345c7fd379", "status": "affected", "version": "9a05475cebdd6341884b5901e53870be26e65158", "versionType": "git"}, {"lessThan": "83fb4c2c5344f02eac929f66de3c9d1adfcde04c", "status": "affected", "version": "9a05475cebdd6341884b5901e53870be26e65158", "versionType": "git"}, {"lessThan": "6335ab62d5fc9ed875279238233fba3462c168f5", "status": "affected", "version": "9a05475cebdd6341884b5901e53870be26e65158", "versionType": "git"}, {"lessThan": "2975324d164c552b028632f107b567302863b7f6", "status": "affected", "version": "9a05475cebdd6341884b5901e53870be26e65158", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/netfilter/ipvs/ip_vs_conn.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "3.10"}, {"lessThan": "3.10", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.261", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.212", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.178", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.145", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.97", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.40", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.5", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2-rc3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-72020", "lastModified": "2026-08-15T06:21:00.920", "metrics": {}, "published": "2026-08-15T06:21:00.920", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2975324d164c552b028632f107b567302863b7f6"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/32c299e28b8eea6cbbd23b97dc61401e9ef9c445"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3bf9a260188b2a5449cbddc032a749ab433fe328"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6335ab62d5fc9ed875279238233fba3462c168f5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6378c5cb360eb1750f88839d7c3613ea92ac1816"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/83fb4c2c5344f02eac929f66de3c9d1adfcde04c"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/9e36602cbec552286f7e691cfd366525c565ee74"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d0eed7177e822cab83141e5c44b2aa345c7fd379"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

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