VulnerabilityPublished 26 Aug 2025

CVE-2025-9431: mtons mblog · Cross-site Scripting

Affects mtons mblogSource CVE Database V5

Public exploit available · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 4.0 base score

5.3Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 29% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/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: None
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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
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 26 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

Immediate mitigation should include implementing strict input validation and output encoding on the 'kw' parameter in the /search endpoint to neutralize any injected scripts.
Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts on mblog pages.
Use web application firewalls (WAFs) to detect and block malicious payloads targeting the vulnerable parameter.
Monitor web server logs for unusual query strings or repeated attempts to exploit the /search endpoint.
If possible, temporarily disable or restrict access to the search functionality until a vendor patch is released.
Educate users about the risks of clicking on suspicious links and encourage reporting of unusual behavior.
Regularly update mblog software once a security patch becomes available from the vendor.
Conduct security audits and penetration testing focused on input handling and XSS vulnerabilities to identify and remediate similar issues proactively.

Description

A flaw has been found in mtons mblog up to 3.5.0. Impacted is an unknown function of the file /search. This manipulation of the argument kw causes cross site scripting. The attack can be initiated remotely. The exploit has been published 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 unauthorized access to user sessions, potentially exposing sensitive information or enabling attackers to perform actions on behalf of legitimate users. This is particularly concerning for organizations that use mblog for internal communications, customer interactions, or content management, where trust and data integrity are critical. The vulnerability could be exploited to conduct targeted phishing campaigns or spread malware by injecting malicious scripts into trusted web pages. While the vulnerability does not directly compromise system availability or allow privilege escalation, the reputational damage and potential data leakage could have regulatory and compliance implications under GDPR and other European data protection laws. Organizations in sectors such as finance, healthcare, and government, which often handle sensitive personal data, may face increased scrutiny and liability if exploited. The medium severity rating reflects the balance between ease of exploitation and the limited scope of impact, but the presence of published exploit code increases urgency for mitigation.

Summary

CVE-2025-9431 is a cross-site scripting (XSS) vulnerability identified in the mtons mblog software, versions 3.0 through 3.5.0. The vulnerability resides in the /search endpoint, specifically involving the manipulation of the 'kw' (keyword) argument. An attacker can craft malicious input that is not properly sanitized or encoded by the application, allowing the injection of arbitrary scripts into the web page viewed by other users. This vulnerability is remotely exploitable without requiring authentication, and user interaction is necessary only in the sense that a victim must visit a maliciously crafted URL or page. The CVSS 4.0 base score is 5.3, indicating a medium severity level. The attack vector is network-based with low attack complexity and no privileges or user authentication required. The impact primarily affects the confidentiality and integrity of the victim’s session or data, as the injected script can steal cookies, session tokens, or perform actions on behalf of the user. Availability impact is not significant. Although no known exploits are currently observed in the wild, the exploit code has been published, increasing the risk of exploitation. The vulnerability does not affect the core security controls of the system but can be leveraged for phishing, session hijacking, or defacement attacks. The lack of a patch link suggests that a fix may not yet be publicly available, emphasizing the need for immediate mitigation steps by administrators of affected mblog instances.

References

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Exploitation evidence

What to do

Affected software

Description

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

Technical details

References

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