CVE-2025-10503: The authentication endpoint accepts user-supplied input without enforcing expected validation constraints, leading to a lack of proper output encoding.

The authentication endpoint accepts user-supplied input without enforcing expected validation constraints, leading to a lack of proper output encoding.

The authentication endpoint accepts user-supplied input without enforcing expected validation constraints, leading to a lack of proper output encoding. This allows for the injection of malicious JavaScript payloads, enabling reflected cross-site scripting. An attacker can leverage this vulnerability to redirect the user's browser to a malicious website, modify the user interface of the web page, retrieve information from the browser, or cause other harmful actions. However, due to the protection of session-related cookies with the httpOnly flag, session hijacking is not possible.

Description from the National Vulnerability Database, published by ed10eef1-636d-4fbe-9993-6890dfa878f8

What it means for a small business

If your business uses WSO2 Identity Server, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.17%, higher than 6% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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