CVE-2026-45250Public exploit

Local privilege escalation via setcred group overflow

Published May 21, 2026 · Updated May 21, 2026

Stack-based buffer overflow in the FreeBSD kernel allows local users to execute arbitrary kernel code through the setcred(2) system call. The kern_setcred_copyin_supp_groups() routine calculates a gid_t array copy with sizeof(*groups), using an eight-byte pointer stride on 64-bit systems to overwrite the fixed-size smallgroups kernel-stack array. Any unprivileged local user can reach the copy before the privilege check; successful control-flow hijacking grants root privileges, while a simpler trigger panics the kernel.

CVSS severity7.8
High
EPSS probability0.41%
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 the FreeBSD kernel allows local users to execute arbitrary kernel code through the setcred(2) system call. The kern_setcred_copyin_supp_groups() routine calculates a gid_t array copy with sizeof(*groups), using an eight-byte pointer stride on 64-bit systems to overwrite the fixed-size smallgroups kernel-stack array. Any unprivileged local user can reach the copy before the privilege check; successful control-flow hijacking grants root privileges, while a simpler trigger panics the kernel.

The record

CVE
CVE-2026-45250
Published
May 21, 2026
Updated
May 21, 2026
Vendor
The FreeBSD Project
Product
FreeBSD
Classifications
CWE-121, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 2026CVE publishedPublication date reported by the CVE source.
  2. May 21, 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 <p14
  2. Affected versionversion=14.4-RELEASE <p5
  3. Affected versionversion=15.0-RELEASE <p9

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The FreeBSD Project · FreeBSDversion=14.3-RELEASE <p14; version=14.4-RELEASE <p5; version=15.0-RELEASE <p9

Published CVSS scores

7.8CISA-ADPCVSS: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.

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 exploitPublished

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1068Exploitation for Privilege Escalation

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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