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

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.

Published: 2025-02-21 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2025-27109 is rated Low Risk (37.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.30%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-27109

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.06% 0.30% +0.25%
2 2026-04-01 0.16% 0.06% -0.10%
3 2025-12-18 0.16%

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-27109

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.3 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
3.9 3.4 [email protected]

Weakness enumeration for CVE-2025-27109

GitHub Security Advisory for CVE-2025-27109

GHSA-3qxh-p7jc-5xh6 · Severity: high · Ecosystem: npm — Solid Lacks Escaping of HTML in JSX Fragments allows for Cross-Site Scripting (XSS)

Affected software / configurations for CVE-2025-27109

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-27109

cvelogic Threat Intelligence