CVE-2026-93105

Local privilege escalation via managed-fragment page underflow

Published Sep 17, 2026 · Updated Sep 18, 2026

Use-after-free in Linux ESP processing allows local users to read and overwrite kernel memory via io_uring zero-copy sends. esp_ssg_unref() releases managed-fragment pages even though the socket buffer acquired no per-fragment references, underflowing counts and freeing live pages. Reaching the flaw requires a registered io_uring buffer, SEND_ZC, and an ESP security association; exploitation can crash the kernel or grant elevated privileges.

CVSS severity7.8
High
EPSS probability0.17%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux ESP processing allows local users to read and overwrite kernel memory via io_uring zero-copy sends. esp_ssg_unref() releases managed-fragment pages even though the socket buffer acquired no per-fragment references, underflowing counts and freeing live pages. Reaching the flaw requires a registered io_uring buffer, SEND_ZC, and an ESP security association; exploitation can crash the kernel or grant elevated privileges.

The record

CVE
CVE-2026-93105
Published
Sep 17, 2026
Updated
Sep 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 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=4.11
  2. Affected versionversion=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <21697720ff43b8dfa25b8e8d9ca7f56f4597fc80
  3. Affected versionversion=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <26b6b14c7a0368e317a1e9fb5144ebe6f8d495cf

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.11; version=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <21697720ff43b8dfa25b8e8d9ca7f56f4597fc80; version=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <26b6b14c7a0368e317a1e9fb5144ebe6f8d495cf

Published CVSS scores

7.8Linux CVE teamCVSS:3.1/AV:L/AC:L/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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

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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