CVE-2026-71236 — HIGH (8.7)

Vulnerability 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. This double-decode reconstructs live HTML/script tags from the entity-encoded form that HTMLPurifier produced to neutralize them, re-introducing stored XSS across API-writable fields (products, recipes, stock, users, chores, and others) that are rendered elsewhere without re-sanitization.

CVSS Score

8.7

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

REQUIRED

Scope

CHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

NONE

Related Weaknesses (CWE)

CWE-79

References

https://github.com/grocy/grocy

FAQ

What is CVE-2026-71236?

CVE-2026-71236 is a vulnerability with a CVSS score of 8.7 (HIGH). Grocy's API request-body parser (controllers/Api/BaseApiController.php, GetParsedAndFilteredRequestBody) purifies incoming field values with HTMLPurifier, then manually reverses HTML-entity encoding o...

How severe is CVE-2026-71236?

CVE-2026-71236 has been rated HIGH with a CVSS base score of 8.7/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-71236?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.