CVE-2025-67846 is a vulnerability identified in the Mintlify Platform's deployment infrastructure prior to the 2025-11-15 patch date. The core issue is that the platform uses predictable deployment identifiers on the Vercel preview domain, which attackers can exploit to perform downgrade attacks. By discovering the URL structure of previous deployments—specifically the git-ref or deployment-id subdomains—an attacker can directly access older versions of the application that contain unpatched vulnerabilities. This external control of assumed-immutable web parameters (CWE-472) allows bypassing of security patches, undermining the integrity of the deployed application. The vulnerability has a CVSS 3.1 base score of 4.9, reflecting a medium severity level with network attack vector, high attack complexity, low privileges required, no user interaction, and partial impact on confidentiality and integrity but no impact on availability. The scope is changed, meaning the vulnerability affects components beyond the initially vulnerable system. No known exploits have been reported in the wild, but the potential for attackers to exploit this flaw to access sensitive or vulnerable application versions is significant. The vulnerability highlights the risks associated with predictable deployment URLs and the importance of securing deployment pipelines and preview environments.

For European organizations using the Mintlify Platform, this vulnerability could lead to unauthorized access to older, vulnerable versions of their applications, potentially exposing sensitive data or allowing attackers to manipulate application behavior. The confidentiality and integrity of data processed or displayed by the affected applications are at risk, as attackers can bypass patches and exploit known vulnerabilities in previous deployments. Although availability is not impacted, the trustworthiness and security posture of affected services may be compromised. This could lead to reputational damage, regulatory compliance issues under GDPR if personal data is exposed, and increased risk of targeted attacks leveraging the unpatched versions. Organizations relying on Mintlify for documentation or deployment services should be particularly cautious, as attackers might exploit this vector to gain footholds or escalate privileges within their environments.

To mitigate CVE-2025-67846, organizations should: 1) Restrict public access to preview deployments and ensure that deployment URLs are not predictable or guessable by unauthorized users. 2) Implement authentication and authorization controls on preview and staging environments to prevent unauthorized browsing of older deployments. 3) Enforce strict version control and continuous patch management to minimize the window of exposure for vulnerable versions. 4) Work with Mintlify to apply the patch released after 2025-11-15 promptly. 5) Monitor deployment URLs and logs for suspicious access patterns indicating attempts to access older deployments. 6) Consider using ephemeral or randomized deployment identifiers to reduce the risk of URL prediction. 7) Educate development and DevOps teams about the risks of exposing preview environments publicly and incorporate security reviews in deployment pipelines. 8) If possible, disable or limit the use of Vercel preview domains for sensitive projects or use private deployment environments.