CVE-2026-71236 Grocy - Stored XSS via HTMLPurifier Output Double-Decode
Attackers can inject malicious scripts into Grocy by exploiting a double-decoding flaw in the API request body parser, potentially leading to session hijacking or code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-71236?
CVE-2026-71236 is a high-severity cross-site scripting vulnerability in grocy, published on 5 Aug 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Grocy's API request-body parser (controllers/Api/BaseApiController.php, GetParsedAndFilteredRequestBody) purifies incoming field values with HTMLPurifier, then manually reverses HTML-entity encoding of the resulting output by replacing &lt;, &gt;, and &amp; back to <, >, and & immediately after purification.
Weakness: CWE-79
Which versions are affected by CVE-2026-71236?
How do I fix CVE-2026-71236?
No fix has been published for CVE-2026-71236 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-71236 being exploited?
There is no known exploitation of CVE-2026-71236 in the wild and no public exploit code.
Sources
Also known as GHSA-c924-wcfj-cr8j.