CVE-2026-49428

Privilege escalation via disallowed largepage frees

Published Aug 19, 2026 · Updated Aug 20, 2026

Use-after-free in FreeBSD before 14.3-RELEASE-p16, 14.4-RELEASE-p7, 15.0-RELEASE-p11, and 15.1-RELEASE-p1 allows local users to gain privileges. The posixshm largepage implementation lets open(2) with O_TRUNC and fspacectl(2) free backing memory even though those operations are invalid for largepage objects. An unprivileged local user who can reach those largepage object paths can access freed kernel memory and leverage the dangling state for privilege escalation.

CVSS severity8.4
High
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in FreeBSD before 14.3-RELEASE-p16, 14.4-RELEASE-p7, 15.0-RELEASE-p11, and 15.1-RELEASE-p1 allows local users to gain privileges. The posixshm largepage implementation lets open(2) with O_TRUNC and fspacectl(2) free backing memory even though those operations are invalid for largepage objects. An unprivileged local user who can reach those largepage object paths can access freed kernel memory and leverage the dangling state for privilege escalation.

The record

CVE
CVE-2026-49428
Published
Aug 19, 2026
Updated
Aug 20, 2026
Vendor
The FreeBSD Project
Product
FreeBSD
Classifications
CWE-915, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 20, 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=14.3-RELEASE <p16
  2. Affected versionversion=14.4-RELEASE <p7
  3. Affected versionversion=15.0-RELEASE <p11
  4. Affected versionversion=15.1-RELEASE <p1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The FreeBSD Project · FreeBSDversion=14.3-RELEASE <p16; version=14.4-RELEASE <p7; version=15.0-RELEASE <p11; version=15.1-RELEASE <p1

Published CVSS scores

8.4CISA-ADPCVSS:3.1/AV:L/AC:L/PR:N/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.

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-915Improperly Controlled Modification of Dynamically-Determined Object Attributes
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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