CVE-2026-49431

Metadata tampering via missing receive check

Published Aug 19, 2026 · Updated Aug 19, 2026

Authorization bypass in FreeBSD allows local users on affected releases to set internal ZFS received-property metadata. In the ZFS_IOC_SET_PROP path, a received-properties request marked by zc_cookie reaches zfs_ioc_set_prop(), which sets the $hasrecvd state, and the fix adds a zfs_secpolicy_recv check so that this mode no longer bypasses receive delegation. Reachability is local through the ZFS ioctl interface; the published impact is unauthorized metadata modification on datasets, with no vendor-reported code execution or privilege-escalation outcome for this CVE.

CVSS severityUnavailable
Unscored
EPSS probability0.12%
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

Authorization bypass in FreeBSD allows local users on affected releases to set internal ZFS received-property metadata. In the ZFS_IOC_SET_PROP path, a received-properties request marked by zc_cookie reaches zfs_ioc_set_prop(), which sets the $hasrecvd state, and the fix adds a zfs_secpolicy_recv check so that this mode no longer bypasses receive delegation. Reachability is local through the ZFS ioctl interface; the published impact is unauthorized metadata modification on datasets, with no vendor-reported code execution or privilege-escalation outcome for this CVE.

The record

CVE
CVE-2026-49431
Published
Aug 19, 2026
Updated
Aug 19, 2026
Vendor
The FreeBSD Project
Product
FreeBSD
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 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=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

No CVSS assessment is available in this record.

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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