6.1
MEDIUM CVSS 3.1
CVE-2026-55877
Symfony UX: XSS in symfony/ux-icons via unsanitized SVG content in local files and Iconify on-demand responses
Description

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 files or Iconify on-demand JSON body responses containing nested script elements, on* event handlers, or dangerous URL schemes to execute cross-site scripting. This issue is fixed in versions 2.36.1 and 3.2.0.

INFO

Published Date :

July 8, 2026, 10:17 p.m.

Last Modified :

July 8, 2026, 10:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-55877 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Update Symfony UX to patched versions to prevent script execution via SVG.
  • Update Symfony UX to 2.36.1 or later.
  • Update Symfony UX to 3.2.0 or later.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-55877.

URL Resource
https://github.com/symfony/ux/commit/3a4964ec3700f0af4e13f7bfbf8bb3174c3e79d1
https://github.com/symfony/ux/releases/tag/v2.36.1
https://github.com/symfony/ux/releases/tag/v3.2.0
https://github.com/symfony/ux/security/advisories/GHSA-6v8j-33hc-mv84
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-55877 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-55877 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-55877 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-55877 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jul. 08, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'symfony', 'product': 'ux', 'versions': [{'status': 'affected', 'version': '>= 2.17.0, < 2.36.1'}, {'status': 'affected', 'version': '>= 3.0.0, < 3.2.0'}]}]
    Added Description 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 files or Iconify on-demand JSON body responses containing nested script elements, on* event handlers, or dangerous URL schemes to execute cross-site scripting. This issue is fixed in versions 2.36.1 and 3.2.0.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    Added CWE CWE-79
    Added Reference https://github.com/symfony/ux/commit/3a4964ec3700f0af4e13f7bfbf8bb3174c3e79d1
    Added Reference https://github.com/symfony/ux/releases/tag/v2.36.1
    Added Reference https://github.com/symfony/ux/releases/tag/v3.2.0
    Added Reference https://github.com/symfony/ux/security/advisories/GHSA-6v8j-33hc-mv84
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.