VulnerabilityPublished 15 Dec 2025

CVE-2023-53892: Blackcat CMS · Unrestricted File Upload

Affects Blackcat CMSSource CVE Database V5

Not known to be exploited · CVSS 8.6 High.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 4.0 base score

8.6High

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

EPSS: 0.9% chance of exploitation in 30 days – higher than 59% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: High
User Interaction: None
Vulnerable system confidentiality: High
Vulnerable system integrity: High
Vulnerable system availability: High
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: High: The attacker requires privileges that provide significant (e.g., administrative) control over the vulnerable system allowing full access to the vulnerable system’s settings and files.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: High: There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Vulnerable system integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the vulnerable system. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the vulnerable system.
Vulnerable system availability: High: There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the Vulnerable System; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the Vulnerable System (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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
blackcat-cms Blackcat CMS	Affected =1.4	Fixed in–

AI-suggested

Immediately restrict administrator access to trusted personnel and enforce strong authentication mechanisms such as multi-factor authentication (MFA) to reduce the risk of credential compromise.
Disable or restrict the jquery plugin manager functionality if feasible until an official patch is available.
Implement strict file upload validation and filtering at the web server or application firewall level to block uploads of zip files containing PHP or other executable scripts.
Monitor web server logs and CMS plugin directories for suspicious uploads or access patterns indicative of exploitation attempts.
Conduct regular audits of administrator accounts and permissions to ensure only authorized users have plugin upload capabilities.
If possible, isolate the CMS environment to limit the impact of a successful exploit, such as running it in a container or sandbox with minimal privileges.
Stay informed about vendor updates and apply official patches promptly once released.
Employ runtime application self-protection (RASP) or web application firewalls (WAF) with custom rules to detect and block attempts to execute arbitrary code via the 'code' parameter or similar vectors.

Description

CVE-2023-53892 is a high-severity remote code execution vulnerability in Blackcat CMS version 1.4. Authenticated administrators can exploit this flaw via the jquery plugin manager by uploading a malicious zip file containing PHP shell scripts. The vulnerability allows execution of arbitrary system commands by accessing the uploaded PHP file with a crafted 'code' parameter. No user interaction or additional authentication beyond admin privileges is required. This vulnerability poses a significant risk to the confidentiality, integrity, and availability of affected systems. Although no known exploits are currently reported in the wild, the ease of exploitation and high impact make timely remediation critical. European organizations using Blackcat CMS 1.4 should prioritize patching or mitigating this vulnerability to prevent potential compromise. Countries with higher adoption of Blackcat CMS or critical infrastructure relying on it are at greater risk.

Impact

For European organizations, exploitation of CVE-2023-53892 could lead to full system compromise, data breaches, and disruption of services hosted on Blackcat CMS 1.4. Attackers with admin credentials can execute arbitrary commands, potentially leading to theft of sensitive information, deployment of ransomware, or use of the compromised server as a pivot point for further network intrusion. This risk is particularly acute for organizations in sectors such as government, finance, healthcare, and critical infrastructure that may use Blackcat CMS for web content management. The vulnerability undermines the confidentiality, integrity, and availability of affected systems, potentially causing reputational damage, regulatory penalties under GDPR, and operational downtime. The absence of known exploits in the wild does not reduce the threat, as the vulnerability is straightforward to exploit once admin access is obtained. European entities with limited security monitoring or outdated CMS versions are especially vulnerable to targeted attacks leveraging this flaw.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 22 Dec 2025, 21:53 UTC

Technical details

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