CVE-2026-72020Network attack vector

Kernel data disclosure via uninitialized IPVS sequence state

Published Aug 15, 2026 · Updated Aug 15, 2026

Uninitialized sequence state in affected Linux kernel versions allows remote attackers to disclose slab data and corrupt TCP flows via sync messages. ip_vs_conn_new() clears only delta after a nonzeroing slab allocation, leaving init_seq and previous_delta stale when ip_vs_proc_conn() imports SEQ flags without sequence data. Exploitation requires an enabled IPVS backup sync receiver and an application helper to process the forged connection; resulting sequence rewrites leak kernel bytes and disrupt forwarded traffic.

CVSS severity9.8
Critical
EPSS probability0.71%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uninitialized sequence state in affected Linux kernel versions allows remote attackers to disclose slab data and corrupt TCP flows via sync messages. ip_vs_conn_new() clears only delta after a nonzeroing slab allocation, leaving init_seq and previous_delta stale when ip_vs_proc_conn() imports SEQ flags without sequence data. Exploitation requires an enabled IPVS backup sync receiver and an application helper to process the forged connection; resulting sequence rewrites leak kernel bytes and disrupt forwarded traffic.

The record

CVE
CVE-2026-72020
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.10
  2. Affected versionversion=9a05475cebdd6341884b5901e53870be26e65158 <2975324d164c552b028632f107b567302863b7f6
  3. Affected versionversion=9a05475cebdd6341884b5901e53870be26e65158 <32c299e28b8eea6cbbd23b97dc61401e9ef9c445
  4. Affected versionversion=9a05475cebdd6341884b5901e53870be26e65158 <3bf9a260188b2a5449cbddc032a749ab433fe328
  5. Affected versionversion=9a05475cebdd6341884b5901e53870be26e65158 <6335ab62d5fc9ed875279238233fba3462c168f5
  6. Affected versionversion=9a05475cebdd6341884b5901e53870be26e65158 <6378c5cb360eb1750f88839d7c3613ea92ac1816
  7. Affected versionversion=9a05475cebdd6341884b5901e53870be26e65158 <83fb4c2c5344f02eac929f66de3c9d1adfcde04c
  8. Affected versionversion=9a05475cebdd6341884b5901e53870be26e65158 <9e36602cbec552286f7e691cfd366525c565ee74
  9. Affected versionversion=9a05475cebdd6341884b5901e53870be26e65158 <d0eed7177e822cab83141e5c44b2aa345c7fd379

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.10; version=9a05475cebdd6341884b5901e53870be26e65158 <2975324d164c552b028632f107b567302863b7f6; version=9a05475cebdd6341884b5901e53870be26e65158 <32c299e28b8eea6cbbd23b97dc61401e9ef9c445; version=9a05475cebdd6341884b5901e53870be26e65158 <3bf9a260188b2a5449cbddc032a749ab433fe328; version=9a05475cebdd6341884b5901e53870be26e65158 <6335ab62d5fc9ed875279238233fba3462c168f5; version=9a05475cebdd6341884b5901e53870be26e65158 <6378c5cb360eb1750f88839d7c3613ea92ac1816; version=9a05475cebdd6341884b5901e53870be26e65158 <83fb4c2c5344f02eac929f66de3c9d1adfcde04c; version=9a05475cebdd6341884b5901e53870be26e65158 <9e36602cbec552286f7e691cfd366525c565ee74; version=9a05475cebdd6341884b5901e53870be26e65158 <d0eed7177e822cab83141e5c44b2aa345c7fd379

Published CVSS scores

9.8kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
5.0Amazon LinuxCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
7.0Oracle LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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