CVE-2026-103523 in Thelia
Summary
by MITRE • 10/12/2026
Thelia v2.6.0 contains an open redirect vulnerability in its address creation workflow. After a user accesses a crafted URL and successfully submits the “Add New Address” form, the application redirects them to the URL specified in the `next` parameter. Because the application does not validate whether the destination belongs to the same origin or an approved allowlist, an attacker can supply an arbitrary external URL and redirect users to an attacker-controlled website.
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Analysis
by VulDB Data Team • 10/12/2026
The vulnerability identified in Thelia version 2.6.0 is a classic open redirect flaw located within the address creation workflow of the application's user interface. This security defect arises from improper validation of input parameters, specifically the `next` parameter which dictates the post-submission redirection target. When a legitimate or malicious actor accesses a crafted URL and successfully submits the Add New Address form, the backend logic unconditionally accepts the value provided in this parameter without performing any checks to ensure it belongs to the same origin or matches an approved allowlist of trusted domains. This lack of validation allows an attacker to inject arbitrary external URLs into the redirect mechanism, effectively hijacking the user's navigation flow after a legitimate action has been completed within the application context.
From a technical perspective, this flaw represents a failure in input sanitization and destination verification during state transitions. The application treats the `next` parameter as trusted data, assuming that because it is part of an internal workflow, its value must be safe to use for redirection. However, by not enforcing strict origin checks or validating against a whitelist of permitted domains, the software exposes itself to manipulation. An attacker can construct a malicious link containing a URL pointing to a phishing site, malware distribution server, or any other external resource under their control. When an unsuspecting user clicks this link and completes the address submission process, they are seamlessly redirected away from the Thelia application to the attacker's designated destination without warning or indication that the domain has changed.
The operational impact of this vulnerability is primarily centered around social engineering attacks and credential theft campaigns. Open redirects are frequently leveraged as a vector for phishing because they lend an air of legitimacy to malicious links. Since the initial part of the URL points to the legitimate Thelia application, users may lower their guard when clicking through to what appears to be a continuation of the service. Once redirected, attackers can present a convincing replica of the login page or other sensitive forms designed to harvest credentials, session cookies, or personal information. This undermines user trust and compromises account security, as stolen sessions or passwords obtained via this method can lead to unauthorized access to customer accounts, administrative panels, or integration with third-party services linked to those accounts.
This vulnerability aligns with CWE-601, which defines Open Redirect URIs, a category of flaws where an application redirects users to URLs provided by the user without proper validation. In terms of offensive security frameworks, this behavior corresponds to ATT&CK technique T1583.002, specifically Domain Registration for Phishing, as it facilitates the setup of deceptive landing pages that appear trustworthy due to their origin linkage. To mitigate this risk, developers must implement strict allowlisting mechanisms where only predefined domains are permitted in redirect parameters. Alternatively, relative paths should be preferred over absolute URLs whenever possible, ensuring that redirections remain within the application's own domain structure. Input validation logic should explicitly reject any external schemes or hostnames not present in a trusted list before processing the request for redirection.