CyberSecBulletin
CVE-2026-49427NVD status: Analyzed

FreeBSD: Premature Release of Resource During Expected Lifetime

CVE-2026-49427 is a high-severity premature release of resource during expected lifetime vulnerability in FreeBSD, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists versions p1, p11, p7 as the first without the flaw, so updating FreeBSD to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.5% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update FreeBSD to p1 or p11 or p7 or p16, whichever matches your release line, or a later version.
  2. Read the advisory on security.freebsd.org for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
FreeBSDFreeBSD15.1-RELEASE up to, but not including, p1; 15.0-RELEASE up to, but not including, p11; 14.4-RELEASE up to, but not including, p7; 14.3-RELEASE up to, but not including, p16p1, p11, p7, p16

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CISA (ADP).

Official description

Pages belonging to largepage shared memory objects were not explicitly wired. When sendfile(2) transmitted such an object with the SF_NOCACHE flag, it freed the underlying pages after transmission even though existing mappings still referred to them. An unprivileged local user can abuse the bug to access freed kernel memory. This can be exploited to escalate privileges.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Premature Release of Resource During Expected Lifetime

The product releases a resource that is still intended to be used by itself or another actor.

More Premature Release of Resource During Expected Lifetime vulnerabilities (CWE-826)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in FreeBSD

All FreeBSD vulnerabilities

Recent Premature Release of Resource During Expected Lifetime vulnerabilities

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