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CVE-2026-8438NVD status: Deferred

All-In-One Security (AIOS) – Security and…: Improper Neutralization of Input During Web Page Generation

CVE-2026-8438 is a high-severity improper neutralization of input during web page generation vulnerability in All-In-One Security (AIOS) – Security and Firewall from Davidanderson, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected All-In-One Security (AIOS) – Security and Firewall versions: 5.4.7 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 8.26% chance of exploitation within 30 days, which is in the top 5.01% of all scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of All-In-One Security (AIOS) – Security and Firewall you run against the affected versions below, and install the vendor's latest release.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
DavidandersonAll-In-One Security (AIOS) – Security and Firewall5.4.7 and earlierNot stated

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
LowNo special conditions are needed; the attack works reliably.
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
LowSome restricted data can be read.
Integrity
LowLimited modification of data is possible.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N. Scored by CNA (wordfence.com).

Official description

The All-In-One Security (AIOS) – Security and Firewall plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to and including 5.4.7. This is due to insufficient input sanitization in the get_rest_route() function and missing output escaping in the column_default() method of the debug log list table. When the 'Disable REST API for non-logged in users' feature (aiowps_disallow_unauthorized_rest_requests) is enabled alongside debug logging (aiowps_enable_debug), an unauthenticated attacker can embed arbitrary HTML or JavaScript in the REST request path. The path is retrieved via urldecode($_SERVER['REQUEST_URI']), which decodes URL-encoded payloads into literal HTML characters. This decoded, unsanitized value is concatenated directly into a debug log message and stored in the database. When an administrator navigates to the AIOS Dashboard Debug Logs page, the column_default() method returns the raw database value without escaping, and the parent list table echoes it directly, causing JavaScript execution in the administrator's browser session. This makes it possible for unauthenticated attackers to inject arbitrary web scripts that execute when an administrator views the debug log page, enabling nonce theft, privileged AJAX/REST actions, and potential full site compromise.

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

The underlying weakness: Improper Neutralization of Input During Web Page Generation

The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

How developers prevent this class of flaw

  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples of libraries and frameworks that make it easier to generate properly encoded output include Microsoft's Anti-XSS library, the OWASP ESAPI Encoding module, and Apache Wicket.
  • Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

More Improper Neutralization of Input During Web Page Generation vulnerabilities (CWE-79)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other references

Recent Improper Neutralization of Input During Web Page Generation vulnerabilities

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