CVE-2026-73432

The account recovery (password reset) functionality in the vulnerability-lookup web application contains a TOCTOU race condition in the consumption of single-use recovery tokens. Two concurrent HTTP requests with the same valid token can both pass verification before either transaction commits, allowing both to set their own password on the target account. Additionally, a secondary defect in the same endpoint allows a valid recovery link to set an empty or trivially short password because form validation is not invoked.

Vulnerability-Lookup has an authentication weakness in account activation and password recovery, where tokens are reusable and not purpose-bound. An attacker who obtains a valid link can repeatedly change the password and take control of the account.

An authorization bypass vulnerability in Vulnerability-Lookup allowed inactive or unconfirmed accounts to subscribe to Server-Sent Events (SSE) streams through the /pubsub/subscribe/<topic> endpoint. The token_required decorator only checked the X-API-KEY header against an existing user API key, without verifying the account's is_active and is_confirmed state. An attacker could create an account and immediately use the API key to access Pub/Sub topics that should only be available to active, confirmed users.

A stored cross-site scripting (XSS) vulnerability existed in Vulnerability-Lookup in the render_tag_badges Jinja filter used to display reference tags associated with vulnerability records. Values from containers.cna.references[].tags[] were directly interpolated into HTML badge elements and wrapped in markupsafe.Markup, bypassing Jinja's automatic HTML escaping. An authenticated user with permissions to create or modify vulnerability records could submit a crafted reference tag through the CNA API containing arbitrary HTML or JavaScript-capable markup.

In Vulnerability-Lookup versions before 2.18.0, a stored XSS vulnerability exists. The backend does not validate or sanitize the related_vulnerabilities field in bundles, and the frontend converts comment and bundle descriptions from Markdown to HTML and injects them directly into the DOM using innerHTML. An attacker who can create or edit comments or bundles can store malicious HTML/JavaScript that will execute in the browser of any user visiting the affected profile page (user.html).

Some endpoints in vulnerability-lookup that modified application state (e.g. changing database entries, user data, configurations, or other privileged actions) may have been accessible via HTTP GET requests without requiring a CSRF token. This flaw leaves the application vulnerable to Cross-Site Request Forgery (CSRF) attacks: an attacker who tricks a logged-in user into visiting a malicious website could cause the user's browser to issue GET requests that perform unintended state-changing operations in the context of their authenticated session.

In affected versions, vulnerability-lookup did not track or limit failed One-Time Password (OTP) attempts during Two-Factor Authentication (2FA) verification. An attacker who already knew or guessed a valid username and password could submit an arbitrary number of OTP codes without causing the account to be locked or generating any specific alert for administrators. This lack of rate-limiting and lockout on OTP failures significantly lowers the cost of online brute-force attacks against 2FA codes and increases the risk of successful account takeover, especially if OTP entropy is reduced (e.g. short numeric codes, user reuse, or predictable tokens). Additionally, administrators had no direct visibility into accounts experiencing repeated 2FA failures, making targeted attacks harder to detect and investigate. The patch introduces a persistent failed_otp_attempts counter on user accounts, locks the user after 5 invalid OTP submissions, resets the counter on successful verification, and surfaces failed 2FA attempts in the admin user list. This enforces an account lockout policy for OTP brute-force attempts and improves monitoring capabilities for suspicious 2FA activity. This issue affects Vulnerability-Lookup: before 2.18.0.

vulnerability-lookup 2.16.0 contains an XSS vulnerability in bundle.py, comment.py, and user.py, which can be exploited by a user of a vulnerability-lookup instance who can add bundles, comments, or sightings. The vulnerability stems from insufficient sanitization of user-supplied input before rendering in templates and tables, allowing injection of arbitrary JavaScript.