CVE-2026-110039

Smush <= 4.3.3 - Missing Authorization

2026-10-14 00:00

Strategic Overview

Status: Patched in 4.3.4
Affected Plugin: Smush – Image Optimization, Compression, Lazy Load, WebP & CDN
Affected Version: <= 4.3.3
CVSS: 2.7Low
Weakness type: CWE-863 · Incorrect Authorization
CVE: CVE-2026-110039

View all Smush – Image Optimization, Compression, Lazy Load, WebP & CDN vulnerabilities

At a glance

CVE-2026-110039 is a low-severity Incorrect Authorization vulnerability in the Smush WordPress plugin, affecting versions <= 4.3.3. It carries a CVSS score of 2.7 (reachable over the network; low attack complexity). The root cause is a missing authorization check on a reachable function. The issue is fixed in version 4.3.4; sites on affected versions should update now. Disclosed October 2026, reported by Erwan LR.

Vulnerability Overview

The Smush plugin for WordPress is vulnerable to unauthorized access in all versions up to, and including, 4.3.3. This is due to a missing capability check on a function. This makes it possible for authenticated attackers, with administrator-level access and above, to perform an unauthorized action.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user.

CWE-863: Incorrect Authorization

Reaching this weakness in Smush <= 4.3.3 takes a caller who can reach the endpoint. Incorrect authorization means a permission check exists but evaluates the wrong thing, so it passes for callers it was meant to stop.

The action runs for users the code intended to exclude, with the same effect as having no check at all. For Smush the fix is 4.3.4: builds <= 4.3.3 are affected, anything from 4.3.4 onward is not.

Remediation

Update to version 4.3.4, or a newer patched version

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: Smush 4.3.4 closes this, and updating the plugin is the step that ends it.

Login Security
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-110039 https://www.wordfence.com/threat-intel/vulnerabilities/id/039223cd-14c3-4ae8-89f8-4b24209cf248 https://nvd.nist.gov/vuln/detail/CVE-2026-110039

Related records

Other vulnerabilities in Smush – Image Optimization, Compression, Lazy Load, WebP & CDN

CVSS Vector

2.7

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredHigh
User InteractionNone
ScopeUnchanged
ConfidentialityNone
IntegrityLow
AvailabilityNone

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