VulnerabilityPublished 7 Jan 2026

CVE-2026-0670: Wikimedia Foundation MediaWiki – ProofreadPage Extension · XSS or 'Cross-site Scripting'

Affects Wikimedia Foundation MediaWiki – ProofreadPage ExtensionSource CVE Database V5

Not known to be exploited · CVSS 6.1 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score

6.1Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Changed
Confidentiality: Low
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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to 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 7 Jan 2026
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
Wikimedia FoundationMediaWiki - ProofreadPage Extension	Affected 1.39 – 1.45 4 affected builds	Fixed in–

AI-suggested

Organizations should monitor for official patches or updates from the Wikimedia Foundation and apply them promptly once available. In the interim, administrators should implement strict input validation and output encoding on all user-supplied content within the ProofreadPage extension. Employing Content Security Policy (CSP) headers can help mitigate the impact of injected scripts by restricting script execution sources. Disabling or restricting the use of the ProofreadPage extension temporarily may be considered if patching is delayed and risk is high. User awareness training to recognize phishing attempts that could trigger malicious links is advisable. Regular security audits and penetration testing focusing on web application vulnerabilities can help identify similar issues proactively. Additionally, configuring MediaWiki to use secure cookies and enforcing HTTPS can reduce session hijacking risks.

Description

CVE-2026-0670 is a medium severity Cross-Site Scripting (XSS) vulnerability in the ProofreadPage extension of Wikimedia Foundation's MediaWiki software versions 1.39, 1.43, 1.44, and 1.45. This vulnerability arises from improper neutralization of input during web page generation, allowing attackers to inject malicious scripts that execute in the context of users' browsers. Exploitation requires user interaction but no authentication, and can lead to limited confidentiality and integrity impacts, such as session hijacking or content manipulation. No known exploits are currently in the wild, and no patches have been linked yet. European organizations using MediaWiki with the ProofreadPage extension, especially those involved in collaborative documentation or digital libraries, should be aware of this risk. Mitigation involves applying patches when available, sanitizing user inputs, and employing Content Security Policies.

Impact

For European organizations, especially those using MediaWiki with the ProofreadPage extension in sectors such as education, cultural heritage, government, and research, this vulnerability poses a risk of session hijacking, unauthorized actions, and misinformation through content manipulation. Attackers could exploit this to steal user credentials or impersonate users, potentially leading to unauthorized access to sensitive information or disruption of collaborative workflows. Although the impact on availability is negligible, the breach of confidentiality and integrity could undermine trust in publicly accessible or internal knowledge bases. The requirement for user interaction limits mass exploitation but targeted phishing or social engineering campaigns could increase risk. Organizations relying heavily on MediaWiki for documentation or digital archiving should consider this vulnerability a moderate threat to their operational security and data integrity.

Summary

CVE-2026-0670 identifies a Cross-Site Scripting (XSS) vulnerability classified under CWE-79 in the ProofreadPage extension of the MediaWiki platform maintained by the Wikimedia Foundation. The vulnerability affects versions 1.39, 1.43, 1.44, and 1.45 of the extension. It stems from improper neutralization of user-supplied input during the generation of web pages, which allows attackers to inject malicious JavaScript code. When a victim user views a crafted page, the injected script executes within their browser context, potentially compromising session tokens, cookies, or enabling actions on behalf of the user. The CVSS 3.1 base score is 6.1 (medium), reflecting network attack vector, low attack complexity, no privileges required, but requiring user interaction. The scope is changed, indicating the vulnerability affects components beyond the initially vulnerable extension, potentially impacting the entire MediaWiki instance. No public exploits or patches are currently documented, indicating the vulnerability is newly disclosed. The ProofreadPage extension is commonly used in environments requiring collaborative proofreading and digitization workflows, making it a target for attackers aiming to compromise user sessions or inject misleading content. The vulnerability does not affect availability but impacts confidentiality and integrity to a limited extent.

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #1OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
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.
Implementation · Architecture and Design
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages.
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide…
OWASP Cheat Sheets
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Injection Prevention (opens in a new tab)
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
OWASP ASVS 4.0.3
V5.3.3 (opens in a new tab)
V1.5.1 (opens in a new tab)
Attack patterns
XSS Using MIME Type Mismatch (opens in a new tab)
DOM-Based XSS (opens in a new tab)
Reflected XSS (opens in a new tab)
Stored XSS (opens in a new tab)
Cross-Site Scripting (XSS) (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 14 Jan 2026, 19:45 UTC

WeaknessesCWE-79

Technical details

References

Community reviews

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