{"apiVersion":"1.0","identifier":"CVE-2026-72020","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.","publishedAt":"2026-08-15T06:21:00","lastModifiedAt":"2026-08-17T06:17:59","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-72020","cvssScore":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","epssProbability":0.00714,"riskScore":1.04,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-72020","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-72020","en":"https://www.redsauce.net/en/cves/CVE-2026-72020","fr":"https://www.redsauce.net/fr/cves/CVE-2026-72020","pt":"https://www.redsauce.net/pt/cves/CVE-2026-72020","de":"https://www.redsauce.net/de/cves/CVE-2026-72020","sk":"https://www.redsauce.net/sk/cves/CVE-2026-72020","el":"https://www.redsauce.net/el/cves/CVE-2026-72020"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-72020"}}