SB2026042888 - Inefficient regular expression complexity in Valibot
Published: April 28, 2026
Security Bulletin ID
SB2026042888
Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Inefficient regular expression complexity (CVE-ID: CVE-2025-66020)
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to inefficient regular expression complexity in EMOJI_REGEX used by the emoji action when processing user-controllable input. A remote attacker can submit a specially crafted short string to cause a denial of service.
The issue is caused by catastrophic backtracking due to overlapping character classes in the regex pattern.
Remediation
Install update from vendor's website.