CVE-2026-80588Network attack vector

Remote denial of service via unreclaimed MPTCP memory

Published Aug 26, 2026 · Updated Aug 27, 2026

Denial of service in Linux kernel MPTCP 6.18.35 through 6.18.45 and 6.19 allows remote attackers to exhaust kernel memory. In net/mptcp/protocol.c, receive-path errors drop socket buffers before queueing without returning borrowed forward allocation to the socket. Any remote peer that completes an MPTCP connection can repeatedly send duplicate or out-of-window mapped data, causing unbounded memory growth and eventual OOM service interruption.

CVSS severity7.5
High
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Denial of service in Linux kernel MPTCP 6.18.35 through 6.18.45 and 6.19 allows remote attackers to exhaust kernel memory. In net/mptcp/protocol.c, receive-path errors drop socket buffers before queueing without returning borrowed forward allocation to the socket. Any remote peer that completes an MPTCP connection can repeatedly send duplicate or out-of-window mapped data, causing unbounded memory growth and eventual OOM service interruption.

The record

CVE
CVE-2026-80588
Published
Aug 26, 2026
Updated
Aug 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-772, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=6.18.35 <6.18.46
  2. Affected versionversion=6.19
  3. Affected versionversion=9db5b3cec4ec1c0cd3239689f5c8653d691a1754 <41b49a8b914ec7dcb03eae93fb27f3c464078644
  4. Affected versionversion=9db5b3cec4ec1c0cd3239689f5c8653d691a1754 <8277f48a06d3aa1441f6d0b6998ccc0360d30ed8
  5. Affected versionversion=a84164847b1e0a106ebc46821e5d2f9b775c9dc8 <473f1a5ab2abc98dd9e74b95b9c23c66c47535cc

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.18.35 <6.18.46; version=6.19; version=9db5b3cec4ec1c0cd3239689f5c8653d691a1754 <41b49a8b914ec7dcb03eae93fb27f3c464078644; version=9db5b3cec4ec1c0cd3239689f5c8653d691a1754 <8277f48a06d3aa1441f6d0b6998ccc0360d30ed8; version=a84164847b1e0a106ebc46821e5d2f9b775c9dc8 <473f1a5ab2abc98dd9e74b95b9c23c66c47535cc

Published CVSS scores

7.5Linux CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

CWE-772Missing Release of Resource after Effective Lifetime
T1499.004Endpoint Denial of Service: Application or System Exploitation

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo