CVE-2026-4747Public exploitNetwork attack vector

Kernel code execution via unchecked credential copy

Published Mar 26, 2026 · Updated Mar 26, 2026

Stack-based buffer overflow in FreeBSD 13.5, 14.3, 14.4, and 15.0 allows remote authenticated users to execute kernel code through NFS. The svc_rpc_gss_validate() routine copies an attacker-controlled RPCSEC_GSS credential body into a 128-byte stack buffer without checking oa_length against the remaining space. Kernel exploitation requires kgssapi.ko to be loaded and the user to reach the NFS server; affected user-space RPC servers permit unauthenticated code execution, but none are known in the base system.

CVSS severity8.8
High
EPSS probability2.49%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in FreeBSD 13.5, 14.3, 14.4, and 15.0 allows remote authenticated users to execute kernel code through NFS. The svc_rpc_gss_validate() routine copies an attacker-controlled RPCSEC_GSS credential body into a 128-byte stack buffer without checking oa_length against the remaining space. Kernel exploitation requires kgssapi.ko to be loaded and the user to reach the NFS server; affected user-space RPC servers permit unauthenticated code execution, but none are known in the base system.

The record

CVE
CVE-2026-4747
Published
Mar 26, 2026
Updated
Mar 26, 2026
Vendor
The FreeBSD Project
Product
FreeBSD
Classifications
CWE-121, T1210
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 26, 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=13.5-RELEASE <p11
  2. Affected versionversion=14.3-RELEASE <p10
  3. Affected versionversion=14.4-RELEASE <p1
  4. Affected versionversion=15.0-RELEASE <p5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The FreeBSD Project · FreeBSDversion=13.5-RELEASE <p11; version=14.3-RELEASE <p10; version=14.4-RELEASE <p1; version=15.0-RELEASE <p5

Published CVSS scores

8.8CISA-ADPCVSS:3.1/AV:N/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.

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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1210Exploitation of Remote Services

Public exploit references

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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