VulnerabilityPublished 21 Mar 2026Updated 16 Apr 2026

CVE-2026-4127: Speedup Optimization (WordPress plugin) · Missing Authorization

Affects Speedup Optimization (WordPress plugin)Source CVE Database V5

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Not known to be exploited · CVSS 4.3 Medium.

Data as of 1 Nov 2026, 22:58 UTC

CVSS 3.1 base score

4.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 21 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 1 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
charlycharmSpeedup Optimization	Affected <=1.5.9	Fixed in–

AI-suggested

Until a fix is available, restrict plugin access to trusted users only and monitor for suspicious POST requests to admin-ajax.php targeting the wp_ajax_speedup01_enabled action. Consider temporarily disabling the plugin if unauthorized changes are suspected.

Description

The Speedup Optimization plugin for WordPress is vulnerable to Missing Authorization in all versions up to and including 1.5.9. The `speedup01_ajax_enabled()` function, which handles the `wp_ajax_speedup01_enabled` AJAX action, does not perform any capability check via `current_user_can()` and also lacks nonce verification. This is in contrast to other AJAX handlers in the same plugin (e.g., `speedup01_ajax_install_iox` and `speedup01_ajax_delete_cache_file`) which properly check for `install_plugins` and `manage_options` capabilities respectively. This makes it possible for authenticated attackers, with Subscriber-level access and above, to enable or disable the site's optimization module by sending a POST request to admin-ajax.

Impact

An attacker with authenticated access at Subscriber level or higher can enable or disable the optimization module of the Speedup Optimization plugin without proper authorization. This could lead to unintended changes in site performance or behavior. The vulnerability does not allow direct confidentiality or availability impacts beyond this configuration change. There are no known exploits in the wild.

Summary

The Speedup Optimization plugin for WordPress contains a missing authorization vulnerability (CWE-862) in the speedup01_ajax_enabled() function. This function processes the wp_ajax_speedup01_enabled AJAX action but fails to perform capability checks using current_user_can() and does not verify nonces. As a result, authenticated users with low privileges (Subscriber and above) can toggle the optimization module on or off by sending a POST request to admin-ajax.php. This contrasts with other AJAX handlers in the plugin that properly enforce capability checks for sensitive actions. The vulnerability is present in all plugin versions up to and including 1.5.9.

CWE-862Missing Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #4OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
Architecture and Design
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Architecture and Design
Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
Attack patterns
Exploitation of Thunderbolt Protection Flaws (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 17 Apr 2026, 11:26 UTC

WeaknessesCWE-862

Technical details

References

Community reviews

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