Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
-
AccessAuthenticate as low-privilege Subscriber
-
ExploitSend crafted get-single-symbol AJAX request
-
ExecutionDeserialize untrusted PHP object, trigger POP chain
-
ImpactOverwrite admin password, gain full admin access
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A08:2025 - Software or Data Integrity Failures
ASVS 5.0
V1 - Encoding and Sanitization Safe deserialization, type allowlists
MITRE ATT&CK
2 techniques across 2 tactics: Execution, Initial Access The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Requires the Kirki (Freeform Page Builder, Website Builder & Customizer) plugin, version ≤6.2.5, installed and active, plus an authenticated account at Subscriber level or above (CVSS PR:L) - no higher privilege and no user interaction (UI:N) are needed. The specific trigger is a request to the 'get-single-symbol' branch of the kirki_post_apis() AJAX dispatcher, which deserializes untrusted input without a capability check; successful privilege escalation also depends on the presence of the described POP chain in the running code. The main limiting factor is the Subscriber-account requirement: sites that allow open user registration are effectively exposed to any visitor, while sites that disable self-registration require the attacker to first obtain a low-privilege account. |
| Impact | Signals are consistent and point to a genuine but non-emergency priority. The CVSS 3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) reflects a high-impact flaw: network-reachable, low attack complexity, only Subscriber-level privileges required, no user interaction, with full confidentiality, integrity and availability impact because the POP chain lets an attacker overwrite an administrator password and take over the site. Against that, the exploitation signals are modest: EPSS is only 0.30% (23rd percentile), the CVE is not listed in CISA KEV, and no public exploit or PoC reference is present in the supplied data - so the low EPSS and absence of exploitation evidence temper the high base score rather than contradict it. The vuln.today Decision label is 'this_week', which aligns with the SSVC-style reading of a high-impact, easily-automatable but not-yet-exploited bug: patch promptly, not as a fire drill. The one real-world amplifier to weigh is PR:L - exploitation needs only a Subscriber account, so any WordPress site running Kirki ≤6.2.5 with open user registration effectively lowers the bar to near-unauthenticated; sites that disable self-registration raise it meaningfully. No signals are missing in a way that changes the verdict, though the exact fixed version is not stated in the input (only a patch changeset reference). |
| Exploit ScenarioDerived | An attacker registers or obtains a low-privilege Subscriber account on a WordPress site running Kirki ≤6.2.5, then sends a crafted AJAX request to the 'get-single-symbol' branch of the kirki_post_apis() dispatcher carrying a serialized PHP object. Because the branch lacks a capability check and deserializes the untrusted input, the payload instantiates an object that drives the available POP chain to overwrite an administrator's password, yielding full administrative access. No public exploit code is identified in the available data, and no user interaction is required. |
Get an e-mail when this CVE is exploited, patched or re-scored. Free account.
Alert meAnalysisAIv1 – Oct 28, 2026
Privilege escalation in the Kirki plugin for WordPress (all versions up to and including 6.2.5) allows authenticated users with only Subscriber-level access to reach a vulnerable deserialization path in the 'get-single-symbol' branch of the kirki_post_apis() AJAX dispatcher, which lacks a capability check, and to inject a PHP object. Because a POP chain is present in the running code, a successful injection can overwrite an administrator's password and hand the attacker full administrative control of the site. The CVSS vector confirms network reachability, low privileges (PR:L), and no user interaction (UI:N) for a high-integrity, high-availability impact; EPSS is low at 0.30% (23rd percentile) and there is no KEV listing, so there is no public exploit identified at time of analysis, though the practical exposure is governed by whether a site permits open user registration.
RemediationAI
Upstream fix available (changeset/commit); released patched version not independently confirmed - the vendor's correction is WordPress.org plugin changeset 3677965 (https://plugins.trac.wordpress.org/changeset/3677965/kirki), so update Kirki to a build that includes that changeset (anything published after 6.2.5) and verify the installed version once a tagged release is confirmed in the plugin repository. Until that update is applied, the exposure is entirely gated by the Subscriber-account requirement: if the site allows open self-registration, disable it or gate registration behind approval or email-domain restrictions, which removes the attacker's foothold but may disrupt legitimate sign-ups; audit existing Subscriber-level accounts for unexpected or recently created users and remove any that are not needed; and if neither is operationally practical, deactivate the Kirki plugin entirely, which eliminates the kirki_post_apis() AJAX endpoint and the attack path at the cost of losing the plugin's builder and customizer functionality on the site.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
The flaw is a PHP Object Injection (CWE-502) rooted in the deserialization of untrusted input. WordPress AJAX handlers registered through kirki_post_apis() are reachable via admin-ajax.php by any logged-in user, including Subscribers, and the 'get-single-symbol' branch of that dispatcher fails to perform a capability check before processing attacker-supplied data through PHP's unserialize path. The absence of that check is what collapses the privilege boundary: a Subscriber can supply a serialized payload rather than a privileged administrator. On its own, object injection is only a primitive; impact here depends on magic methods (__wakeup, __destruct, __toString) in classes loaded during the request forming a usable POP chain, which the advisory states is present and can be chained to an administrator password overwrite. The CPE string identifies the affected package as Themeum's 'Kirki - Freeform Page Builder, Website Builder & Customizer' for WordPress, and ENISA EUVD records the affected range as versions 0 through 6.2.5, matching the plugin's own release history. Fixing this requires both a capability/permission check on the AJAX branch and, ideally, avoidance of unserialize on user-controlled input (for example JSON or an allowed-classes restriction).
Know when PHP gets its next vulnerability
- Watch products and get an email when something new is published
- Check this CVE against your own stack and servers
- Exploit and PoC references, threat intelligence from 22 sources
No credit card · 7-day full trial
Severity by source
AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Network-reachable AJAX endpoint (AV:N/AC:L), needs only a Subscriber account so PR:L, no interaction (UI:N); admin takeover yields full C/I/A impact with no scope change.
Primary rating from Vendor (Wordfence).
CVSS VectorNVD
DescriptionNVD
The Kirki plugin for WordPress is vulnerable to Privilege Escalation via PHP Object Injection in all versions up to, and including, 6.2.5 via deserialization of untrusted input through the 'get-single-symbol' branch of the kirki_post_apis() AJAX dispatcher due to a missing capability check. This makes it possible for authenticated attackers, with Subscriber-level access and above, to inject a PHP Object. The additional presence of a POP chain allows attackers to overwrite an administrator's password and gain administrative access.
Executive ViewAI
CVE-2026-75891 is a high-severity privilege escalation in the Kirki WordPress plugin (all versions through 6.2.5) that lets any authenticated Subscriber take full administrative control of a site. Every WordPress installation running Kirki with open user registration is affected, exposing content, user data, and site integrity to a low-skill insider or self-registered attacker. Leadership should care because unpatched sites remain continuously exposed and a compromise could damage brand trust and require costly recovery.
No vendor-released patch identified at time of analysis. Interim mitigations: disable open user registration to block unauthenticated creation of Subscriber accounts; deactivate the Kirki plugin if business operations permit; enforce least privilege by reviewing and minimizing Subscriber accounts; enable web application firewall rules to block crafted requests to the plugin's AJAX endpoint; monitor for anomalous administrative password changes.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Privilege escalation occurs when an attacker leverages flaws in access control mechanisms to gain permissions beyond what they were originally granted.
Insecure deserialization occurs when an application converts serialized data (a stream of bytes representing an object's state) back into a living object without proper validation.
In PHP versions 7.1.x below 7.1.33, 7.2.x below 7.2.24 and 7.3.x below 7.3.11 in certain configurations of FPM setup it
sapi/cgi/cgi_main.c in PHP before 5.3.12 and 5.4.x before 5.4.2, when configured as a CGI script (aka php-cgi), does not
(1) boardData102.php, (2) boardData103.php, (3) boardDataJP.php, (4) boardDataNA.php, and (5) boardDataWW.php in Netgear
The '/common/download_agent_installer.php' script in the Quest KACE System Management Appliance 8.0.318 is accessible by
ProjectSend versions prior to r1720 are affected by an improper authentication vulnerability. Rated critical severity (C
Roundcube Webmail contains a critical PHP object deserialization vulnerability (CVE-2025-49113, CVSS 9.9) that allows au
Util/PHP/eval-stdin.php in PHPUnit before 4.8.28 and 5.x before 5.6.3 allows remote attackers to execute arbitrary PHP c
Palo Alto Networks PAN-OS management web interface contains an authentication bypass allowing unauthenticated attackers
Nagios XI version xi-5.7.5 is affected by OS command injection. Rated high severity (CVSS 8.8), this vulnerability is re
Nagios XI version xi-5.7.5 is affected by OS command injection. Rated high severity (CVSS 8.8), this vulnerability is re
The get_referers function in /opt/ws/bin/sblistpack in Sophos Web Appliance before 3.7.9.1 and 3.8 before 3.8.1.1 allows
The Backup Migration plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 1
EUVD-2026-110629
GHSA-ppv3-rhmr-8mqr
NVD
CVE.org
EPSS
Exploit-DB