CVE-2026-55877 json
Symfony UX: XSS in symfony/ux-icons via unsanitized SVG content in local files and Iconify on-demand responses
published 4mo ago modified 17d ago also EUVD-2026-42444 , GHSA-6v8j-33hc-mv84
- cvss
- 6.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 27%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- packagist symfony/ux-icons 2.36.1, 3.2.0
- symfony ux 2.36.1, 3.2.0
Is CVE-2026-55877 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 4mo ago
Exploit prediction
0.34% chance of exploitation in the next 30 days, higher than 27% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| GitHub | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| packagist | symfony/ux-icons | >=2.17.0, <2.36.1 >=3.0.0, <3.2.0 |
2.36.1 3.2.0 |
Affected products
- symfony ux
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
github.com
/symfony/ux/commit/3a4964ec3700f0af4e13f7bfbf8bb3174c3e79d1
patch
-
github.com
/symfony/ux/security/advisories/GHSA-6v8j-33hc-mv84
web, vendor-advisory
-
github.com
/symfony/ux/releases/tag/v2.36.1
release-notes
-
github.com
/symfony/ux/releases/tag/v3.2.0
release-notes
-
github.com
/FriendsOfPHP/security-advisories/blob/master/symfony/ux-icons/CVE-2026-55877.yaml
web
-
github.com
/symfony/ux
package
Sources
- CVE List CVE-2026-55877
- GitHub Advisory GHSA-6v8j-33hc-mv84
- NVD CVE-2026-55877
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.