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CVE-2026-94267NVD status: Deferred

Advanced Custom Fields: Extended: Improper Control of Generation of Code

CVE-2026-94267 is a critical-severity improper control of generation of code vulnerability in Advanced Custom Fields: Extended, with a CVSS 3.1 base score of 9.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 0.9.2.8 as the first without the flaw, so updating Advanced Custom Fields: Extended to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.39% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Advanced Custom Fields: Extended to 0.9.2.8 or a later version.
  2. Update Advanced Custom Fields: Extended PRO to 0.9.2.8 or a later version.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H. Scored by CISA (ADP).

Official description

The Advanced Custom Fields: Extended WordPress plugin before 0.9.2.8, Advanced Custom Fields: Extended PRO WordPress plugin before 0.9.2.8 does not perform any capability check when updating a post through one of its front-end form actions, allowing unauthenticated visitors to overwrite arbitrary posts, including the ones in which the site stores its own field definitions, which in turn leads to arbitrary code execution on the server. Exploitation requires the site to publish a form whose post-update action maps both its target and its content to visitor-submitted values.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Control of Generation of Code

The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

How developers prevent this class of flaw

  • Refactor your program so that you do not have to dynamically generate code.
  • Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
  • Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.

More Improper Control of Generation of Code vulnerabilities (CWE-94)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).

References

Other vulnerabilities in Advanced Custom Fields: Extended

All Advanced Custom Fields: Extended vulnerabilities

Recent Improper Control of Generation of Code vulnerabilities

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