CVE-2026-33741CWE-79

EspoCRM: Stored XSS via SVG attachment loading same-origin JavaScript

Medium · published May 19, 2026

CVSS v3.1
6.8
EPSS
0%
Percentile
19.0
In the wild
Unconfirmed
What it is

EspoCRM is an open source customer relationship management application. Versions 9.3.3 and below allow authenticated users to upload SVG attachments through normal attachment-capable fields and later serve those SVG files as top-level inline documents through both the attachment and image entry points, resulting in stored cross-user XSS reachable through a normal attachment workflow. Although inline SVG script is blocked by the response CSP, the same CSP still allows same-origin external script. As a result, an attacker can upload a malicious SVG together with a second attacker-controlled JavaScript attachment, then trick another user into opening the SVG to execute JavaScript in the victim's EspoCRM origin. This issue has been fixed in version 9.3.4.

The record
Technical detail
CVSS v3.1
6.8 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:L
CVSS v4.0
Not supplied
EPSS
0.00276 · 19.0th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-05-19T18:14Z
EPSS history
Timeline
  • 19 MAY 18:14Z
    EspoCRM: Stored XSS via SVG attachment loading same-origin JavaScript
    cvelistv5