VulnerabilityPublished 25 Aug 2025

CVE-2025-9429: mtons mblog · Cross-site Scripting

Affects mtons mblogSource CVE Database V5

Public exploit available · CVSS 5.1 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 4.0 base score

5.1Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 19% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Base metrics

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

Threat metrics

Exploit Maturity: POC

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: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: Passive: Successful exploitation of this vulnerability requires limited interaction by the targeted user with the vulnerable system and the attacker’s payload. These interactions would be considered involuntary and do not require that the user actively subvert protections built into the vulnerable system.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system 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 to the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
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.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Aug 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CVSS exploit maturity: proof of concept public
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), CVSS vector, 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
mtons mblog	Affected 3.0 – 3.5.0 6 affected builds	Fixed in–

AI-suggested

To mitigate this vulnerability, organizations should immediately upgrade mtons mblog to a version beyond 3.5.0 where the vulnerability is patched, if available. If an upgrade is not immediately possible, implement strict input validation and output encoding on the 'content' and 'title' parameters at the application level to neutralize malicious scripts. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. Additionally, enable HTTP-only and secure flags on cookies to reduce session hijacking risks. Regularly audit and monitor web application logs for suspicious activities related to post submissions. Educate users to be cautious of unexpected links or posts, especially those containing user-generated content. Finally, consider deploying web application firewalls (WAFs) configured to detect and block XSS attack patterns targeting the mblog platform.

Description

A security vulnerability has been detected in mtons mblog up to 3.5.0. This vulnerability affects unknown code of the file /post/submit of the component Post Handler. The manipulation of the argument content/title/ leads to cross site scripting. It is possible to initiate the attack remotely. The exploit has been disclosed publicly and may be used.

Impact

For European organizations using mtons mblog (versions up to 3.5.0), this vulnerability poses a moderate risk. Exploitation could lead to compromise of user sessions, unauthorized actions performed on behalf of users, or distribution of malicious content to visitors. This can damage organizational reputation, lead to data leakage of user information, and potentially facilitate further attacks within the network if administrative users are targeted. Given that mblog is a blogging platform, organizations relying on it for public communication or internal knowledge sharing could face disruption or loss of user trust. The impact is heightened in sectors with strict data protection regulations such as GDPR, where exploitation leading to personal data exposure could result in regulatory penalties. However, the vulnerability does not directly affect system availability or confidentiality at a critical level, limiting the scope of damage to primarily integrity and user trust.

Summary

CVE-2025-9429 is a cross-site scripting (XSS) vulnerability identified in the mtons mblog software versions up to 3.5.0. The vulnerability resides in the /post/submit endpoint within the Post Handler component, specifically affecting the handling of the 'content' and 'title' parameters. An attacker can remotely exploit this flaw by injecting malicious scripts into these parameters, which are then improperly sanitized or validated before being rendered in the application. This allows the attacker to execute arbitrary JavaScript code in the context of users visiting the affected mblog instance. The vulnerability requires no authentication but does require user interaction (such as a victim clicking a crafted link or viewing a malicious post) to trigger the script execution. The CVSS 4.0 base score is 5.1 (medium severity), reflecting network attack vector, low attack complexity, no privileges required, but user interaction needed, and limited impact on integrity and availability with no impact on confidentiality. Although no known exploits are currently observed in the wild, the public disclosure of the exploit code increases the risk of exploitation. XSS vulnerabilities like this can be leveraged for session hijacking, phishing, defacement, or delivering further malware payloads, impacting the trustworthiness and security of the affected blogging platform.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 2 Sep 2025, 01:02 UTC

Technical details

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