CVE-2026-33741: EspoCRM: Stored XSS via SVG attachment loading same-origin JavaScript

Published May 19, 2026
·
Updated

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.

Affected Software

1 affected component
EspoCRM EspoCRM<=9.3.3

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade EspoCRM to a version that resolves this vulnerability.

    Fixed in 9.3.4
  2. Compensating control

    Restrict who can upload SVG attachments via attachment-capable fields until EspoCRM is upgraded to 9.3.4, since versions 9.3.3 and below allow authenticated users to upload SVGs that can execute stored cross-user XSS when served as top-level inline documents.

Event History

May 19, 2026
CVE Published
via MITRE·06:14 PM
Data Sourced
via MITRE·06:14 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·07:16 PM
DescriptionSeverityWeakness

Frequently Asked Questions

1

What is the severity of CVE-2026-33741?

CVE-2026-33741 has a severity rating that depends on the potential impact of stored XSS attacks in EspoCRM.

2

How do I fix CVE-2026-33741?

To fix CVE-2026-33741, upgrade EspoCRM to a version above 9.3.3 that mitigates the stored XSS vulnerability.

3

What versions of EspoCRM are affected by CVE-2026-33741?

EspoCRM versions 9.3.3 and below are affected by CVE-2026-33741.

4

What type of vulnerability is CVE-2026-33741?

CVE-2026-33741 is classified as a stored cross-site scripting (XSS) vulnerability.

5

Who is affected by CVE-2026-33741?

Authenticated users of EspoCRM are affected by CVE-2026-33741 due to the ability to upload malicious SVG attachments.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203