CVE-2025-55203: Plane is open-source project management software.

Plane is open-source project management software.

Plane is open-source project management software. Prior to version 0.28.0, a stored cross-site scripting (XSS) vulnerability exists in the description_html field of Plane. This flaw allows an attacker to inject malicious JavaScript code that is stored and later executed in other users’ browsers. The description_html field is not properly sanitized or escaped. An attacker can submit crafted JavaScript payloads that are saved in the application’s database. When another user views the affected content, the injected code executes in their browser, running in the application’s context and bypassing standard security protections. Successful exploitation can lead to session hijacking, theft of sensitive information, or forced redirection to malicious sites. The vulnerability can also be chained with CSRF attacks to perform unauthorized actions, or leveraged to distribute malware and exploit additional browser vulnerabilities. This issue has been patched in version 0.28.0.

Description from the National Vulnerability Database, published by GitHub

What it means for a small business

If your business uses plane, 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 0.21%, higher than 11% 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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