CVE-2026-55877

Symfony UX: XSS in symfony/ux-icons via unsanitized SVG content in local files and Iconify on-demand responses

MEDIUM
6.1
CVSS Score
Published: July 8, 2026 at 09:32 PM UTC
Updated: October 25, 2026 at 05:10 PM UTC
1 product affected across 1 vendorUx

Using ux by symfony?

Get instant alerts when new vulnerabilities affect ux - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM6.1
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

2.17.0 ≤ v < 2.36.13.0.0 ≤ v < 3.2.0
Affected range stops below 2.36.1, so it looks safe — our inference, not a vendor statement
Affected range stops below 3.2.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (4)

x_refsource_CONFIRMVendor Advisory
Source: cverecord
https://github.com/symfony/ux/security/advisories/GHSA-6v8j-33hc-mv84
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/symfony/ux/releases/tag/v2.36.1
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/symfony/ux/releases/tag/v3.2.0

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.1MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-79

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card