XSS in Symfony Ux
CVE-2026-55877
Symfony UX is a JavaScript ecosystem for Symfony. From 2.17.0 before 2.36.1 and from 3.0.0 before 3.2.0, the ux_icon() Twig function is marked is_safe=['html'] and Icon::toHtml() inlines SVG source verbatim, allowing unsanitized local SVG…
Vulnerability class: XSS (Cross-Site Scripting)
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
Affected products
- Symfony Ux — versions >= 2.17.0, < 2.36.1, >= 3.0.0, < 3.2.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-55877?
- CVE-2026-55877 is a medium-severity vulnerability in Symfony Ux, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-07-08.
- How severe is CVE-2026-55877?
- Medium severity. CVSS v3 base score is 6.1 out of 10.