CVE-2026-104453 in YesWiki
Summary
by MITRE • 10/02/2026
YesWiki before 4.6.7 contains a cross-site request forgery vulnerability in the admintag action that allows attackers to delete tag associations by luring administrators to crafted GET links. Attackers can supply a wide id range in the delete_tag parameter via top-level navigation, carrying the SameSite=Lax admin cookie, to bulk-delete tag triples.
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Analysis
by VulDB Data Team • 10/02/2026
YesWiki versions prior to 4.6.7 are susceptible to a critical cross-site request forgery vulnerability within the admintag action module. This flaw stems from insufficient validation of state-changing requests that rely on HTTP GET methods for administrative operations, specifically those involving tag management. The core technical deficiency lies in the application's failure to implement robust anti-CSRF tokens or strict origin checking mechanisms for actions that modify database states. By exploiting this weakness, an attacker can craft malicious URLs containing specific parameters designed to trigger unintended side effects when accessed by a privileged user who is currently authenticated with administrative privileges.
The operational mechanism of this vulnerability involves the manipulation of the delete_tag parameter through top-level navigation elements or embedded links within external web pages. When an administrator clicks on such a crafted link, their browser automatically attaches session cookies, including those configured with SameSite=Lax attributes, to the request. Although the Lax policy restricts cookie sending in some cross-site contexts, it still permits them for top-level navigations initiated by user interaction, which is precisely what this attack leverages. The attacker can supply a wide range of identifiers within the delete_tag parameter, allowing for the bulk deletion of tag triples associated with wiki pages. This capability transforms a simple link click into a powerful tool for data destruction without requiring any prior knowledge of session tokens or complex exploitation techniques beyond social engineering to lure the victim administrator.
The impact of this vulnerability is significant as it compromises both the integrity and availability of the wiki content managed by YesWiki. Tag associations are often used for categorization, searchability, and metadata management within the platform. The bulk deletion of these triples can lead to a disorganized knowledge base where pages lose their contextual links and classification structure. Furthermore, if tags are linked to access control lists or automated workflows, their removal could inadvertently expose sensitive content or disrupt operational processes dependent on those specific identifiers. This represents a direct threat to data integrity, as the attacker effectively alters system state without authorization by abusing the trust relationship between the browser and the web application.
From a classification perspective, this vulnerability aligns with CWE-352, which describes Cross-Site Request Forgery (CSRF), specifically highlighting the lack of verification for user identity in state-changing requests. It also relates to CWE-614 regarding insufficient session identifier validation during administrative actions. In terms of offensive security frameworks, this attack vector corresponds to MITRE ATT&CK technique T1556.003, which involves modifying authentication processes through credential or token theft and abuse, although in this case, it is more accurately mapped to the broader category of abusing trusted relationships for unauthorized state changes. The exploitation relies on the victim's authenticated session being hijacked via a forged request rather than direct credential compromise, fitting into patterns observed in social engineering-driven attacks against web applications.
To mitigate this vulnerability, immediate updates to YesWiki version 4.6.7 or later are required as they address these security flaws. For environments where upgrading is not immediately feasible, administrators should implement additional defensive measures such as enforcing strict SameSite cookie attributes set to Strict rather than Lax for administrative sessions, ensuring that cookies are never sent with cross-site requests regardless of navigation context. Additionally, integrating anti-CSRF tokens into all state-changing GET and POST requests provides a robust layer of defense by requiring unique, unpredictable values tied to the user's session. Implementing custom request headers or validating the Origin header can further prevent unauthorized actions initiated from external domains. Regular security audits focusing on input validation for administrative endpoints will help identify similar weaknesses in other modules before they can be exploited.