CVE-2026-72020ipvs: reset full ip_vs_seq structs in ip_vs_conn_new
- 9.8CriticalCVSS base score
- 0.71%Exploitation in 30 daysEPSS · top 46% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By Linux
- 6 days later
· 6 days later
Published
- 2 months later
· 2 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Received | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.71% · top 46% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
- affected 9a05475cebdd6341884b5901e53870be26e65158 – < 3bf9a260188b2a5449cbddc032a749ab433fe328
- affected 9a05475cebdd6341884b5901e53870be26e65158 – < 6378c5cb360eb1750f88839d7c3613ea92ac1816
- affected 9a05475cebdd6341884b5901e53870be26e65158 – < 32c299e28b8eea6cbbd23b97dc61401e9ef9c445
- affected 9a05475cebdd6341884b5901e53870be26e65158 – < 9e36602cbec552286f7e691cfd366525c565ee74
- affected 9a05475cebdd6341884b5901e53870be26e65158 – < d0eed7177e822cab83141e5c44b2aa345c7fd379
- affected 9a05475cebdd6341884b5901e53870be26e65158 – < 83fb4c2c5344f02eac929f66de3c9d1adfcde04c
- affected 9a05475cebdd6341884b5901e53870be26e65158 – < 6335ab62d5fc9ed875279238233fba3462c168f5
- affected 9a05475cebdd6341884b5901e53870be26e65158 – < 2975324d164c552b028632f107b567302863b7f6
- affected 3.10
- unaffected < 3.10
- unaffected 5.10.261 – ≤ 5.10.*
- unaffected 5.15.212 – ≤ 5.15.*
- unaffected 6.1.178 – ≤ 6.1.*
- unaffected 6.6.145 – ≤ 6.6.*
- unaffected 6.12.97 – ≤ 6.12.*
- unaffected 6.18.40 – ≤ 6.18.*
- unaffected 7.1.5 – ≤ 7.1.*
- unaffected 7.2 – ≤ *
References
References8
- https://git.kernel.org/stable/c/3bf9a260188b2a5449cbddc032a749ab433fe328 (opens in a new tab)
- https://git.kernel.org/stable/c/6378c5cb360eb1750f88839d7c3613ea92ac1816 (opens in a new tab)
- https://git.kernel.org/stable/c/32c299e28b8eea6cbbd23b97dc61401e9ef9c445 (opens in a new tab)
- https://git.kernel.org/stable/c/9e36602cbec552286f7e691cfd366525c565ee74 (opens in a new tab)
- https://git.kernel.org/stable/c/d0eed7177e822cab83141e5c44b2aa345c7fd379 (opens in a new tab)
- https://git.kernel.org/stable/c/83fb4c2c5344f02eac929f66de3c9d1adfcde04c (opens in a new tab)
- https://git.kernel.org/stable/c/6335ab62d5fc9ed875279238233fba3462c168f5 (opens in a new tab)
- https://git.kernel.org/stable/c/2975324d164c552b028632f107b567302863b7f6 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-58978 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-72020)Record last updated .