CVE-2025-27109: Lack of Escaping of HTML in JSX Fragments allows for Cross-site Scripting in solid-js

Severity: high (CVSS 7.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-02-21 · updated 2026-06-17
Weakness: CWE-79

Description

solid-js is a declarative, efficient, and flexible JavaScript library for building user interfaces. In affected versions Inserts/JSX expressions inside illegal inlined JSX fragments lacked escaping, allowing user input to be rendered as HTML when put directly inside JSX fragments. This issue has been addressed in version 1.9.4 and all users are advised to upgrade. There are no known workarounds for this vulnerability.

Affected products

solidjs solid: before 1.9.4

References

https://github.com/solidjs/solid/commit/b93956f28ed75469af6976a98728e313d0edd236
https://github.com/solidjs/solid/security/advisories/GHSA-3qxh-p7jc-5xh6
https://github.com/solidjs/solid/security/advisories/GHSA-3qxh-p7jc-5xh6

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