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CVE-2026-42512

Remotely triggerable out-of-bounds heap write in dhclient

HIGH
8.1
CVSS Score
Published: April 30, 2026 at 07:58 AM UTC
Updated: June 17, 2026 at 10:47 AM UTC
1 product affected across 1 vendorFreeBSD

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Severity
HIGH8.1
Exploit prediction
EPSS 1%
SSVC
No known exploit

Description

As dhclient is building an environment to pass to dhclient-script, it may need to resize the array of string pointers. The code which expands the array incorrectly calculates its new size when requesting memory, resulting in a heap buffer overrun. A specially crafted packet can cause dhclient to overrun its buffer of environment entries. This can result in a crash, but it may be possible to leverage this bug to achieve remote code execution.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

FreeBSD· Freebsd
95%
13.5-RELEASE ≤ v < p1314.3-RELEASE ≤ v < p1214.4-RELEASE ≤ v < p315.0-RELEASE ≤ v < p713.513.5 beta313.5 p113.5 p1013.5 p1113.5 p1213.5 p213.5 p313.5 p413.5 p513.5 p613.5 p713.5 p813.5 p913.5-RELEASE14.314.3 p114.3 p1014.3 p1114.3 p214.3 p314.3 p414.3 p514.3 p614.3 p714.3 p814.3 p914.3-RELEASE14.414.4 p114.4 p214.4 rc114.4-RELEASE15.015.0 p115.0 p215.0 p315.0 p415.0 p515.0 p615.0-RELEASE
Affected range stops below p12, so it looks safe — our inference, not a vendor statement
Affected range stops below p13, so it looks safe — our inference, not a vendor statement
Affected range stops below p3, so it looks safe — our inference, not a vendor statement
Affected range stops below p7, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (1)

Vendor Advisory
Source: cverecord
https://security.freebsd.org/advisories/FreeBSD-SA-26:15.dhclient.asc

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.1HIGHCISA-ADP
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-122

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