CVE-2026-59994: XSS (CVSS 4.3)

Description

EspoCRM is an open source customer relationship management application. Prior to 9.3.9, an unauthenticated remote attacker can send an email to a monitored group or IMAP address, including an email-to-Case address, and place arbitrary HTML in its plain-text body. EspoCRM stores that body and renders it without escaping in Email Received stream notification emails sent to users following the related record, allowing HTML injection and, in mail clients that execute it, JavaScript execution. Earlier sanitization for Post and Mention notifications did not cover this notification path. This issue is fixed in version 9.3.9.

Is your site exposed to CVE-2026-59994?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

4.3

MEDIUM

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

EPSS — Exploit Prediction

0.0035

Probability of exploitation

0.28%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

References

Other References

https://github.com/espocrm/espocrm/commit/f9fd47622df04617728643b4b8f1a22563cbc6e7 https://github.com/espocrm/espocrm/releases/tag/9.3.9 https://github.com/espocrm/espocrm/security/advisories/GHSA-3rh4-9hcq-g79m

Frequently Asked Questions

What is CVE-2026-59994? +

EspoCRM is an open source customer relationship management application. Prior to 9.3.9, an unauthenticated remote attacker can send an email to a monitored group or IMAP address, including an email-to-Case address, and place arbitrary HTML in its plain-text body. EspoCRM stores that body and renders it without escaping in Email Received stream notification emails sent to users following the related record, allowing HTML injection and, in mail clients that execute it, JavaScript execution. Earlier sanitization for Post and Mention notifications did not cover this notification path. This issue is fixed in version 9.3.9. It has a CVSS v3.1 base score of 4.3 (MEDIUM).

How severe is CVE-2026-59994? +

CVE-2026-59994 has a CVSS v3.1 score of 4.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0035, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-59994? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-40282

WeGIA is a web manager for charitable institutions. In versions prior to 3.6.10, a Stored Cross-Site Scripting (XSS) vulnerability allows …

CVE-2026-3317

Reflected Cross-Site Scripting (XSS) vulnerability in Navigate Content Management System. The vulnerability is present in the '/blog' endpoint because user …

CVE-2025-10354

Cross-Site Scripting (XSS) vulnerability reflected in Semantic MediaWiki. This vulnerability allows an attacker to execute JavaScript code in the victim's …

CVE-2026-41456

Bludit CMS prior to commit 6732dde contains a reflected cross-site scripting vulnerability in the search plugin that allows unauthenticated attackers …

CVE-2026-40872

mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the admin dashboard's Autodiscover …

CVE-2026-40878

mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the mailcow web interface …