Linux kernel IPVS is widely used (LVS, kube-proxy); this bug can disrupt or corrupt load‑balanced TCP flows across organizations.
CVE-2026-72020
IPVS uninitialized seq fields allow crafted sync messages to corrupt TCP seq/ack numbers.
Is CVE-2026-72020 being exploited?
Not confirmed. CVE-2026-72020 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.71% probability of exploitation in the next 30 days.
How severe is CVE-2026-72020?
CVE-2026-72020 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-72020?
Yes. A fix has been recorded for CVE-2026-72020. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-72020 affect?
CVE-2026-72020 affects Linux kernel (ipvs module), LVS/IPVS load balancers, kube-proxy (IPVS mode), keepalived / ipvsadm-managed hosts, and 1 further product or version. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-72020?
Apply kernel update with IPVS fix, restart IPVS/kube-proxy, block untrusted IPVS sync sources.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Crafted IPVS sync messages can force forwarded packets to carry corrupted TCP seq/ack, disrupting or corrupting TCP flows and enabling flow manipulation.
Immediate action required
- affected>= 9a05475cebdd6341884b5901e53870be26e65158 and < 3bf9a260188b2a5449cbddc032a749ab433fe328
- affected>= 9a05475cebdd6341884b5901e53870be26e65158 and < 6378c5cb360eb1750f88839d7c3613ea92ac1816
- affected>= 9a05475cebdd6341884b5901e53870be26e65158 and < 32c299e28b8eea6cbbd23b97dc61401e9ef9c445
- affected>= 9a05475cebdd6341884b5901e53870be26e65158 and < 9e36602cbec552286f7e691cfd366525c565ee74
- affected>= 9a05475cebdd6341884b5901e53870be26e65158 and < d0eed7177e822cab83141e5c44b2aa345c7fd379
- affected>= 9a05475cebdd6341884b5901e53870be26e65158 and < 83fb4c2c5344f02eac929f66de3c9d1adfcde04c
- affected>= 9a05475cebdd6341884b5901e53870be26e65158 and < 6335ab62d5fc9ed875279238233fba3462c168f5
- affected>= 9a05475cebdd6341884b5901e53870be26e65158 and < 2975324d164c552b028632f107b567302863b7f6
- affected3.10
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.