CVE-2026-42512
Remotely triggerable out-of-bounds heap write in dhclient
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Remotely triggerable out-of-bounds heap write in dhclient
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.
- Record
CVE-2026-42512- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-122
- Updated
- 2026-11-02
EUVDEUVD-2026-26357
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.
- Record
EUVD-2026-26357- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-6r9j-w82p-v45p
As dhclient is building an environment to pass to dhclient-script, it may need to resize the...
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.
- Record
GHSA-6r9j-w82p-v45p- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - Weakness
- CWE-122
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-42512- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-122
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-42512 is a high vulnerability (CVSS 8.1) in Freebsd, published April 30, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.42%, the 73rd percentile. No source names a fixed version.