CVE-2026-46364: phpMyFAQ - SQL Injection via User-Agent Header in BuiltinCaptcha

Vulnerability summary

CVE-2026-46364 is a critical (CVSS 9.8) SQL Injection vulnerability in thorsten phpmyfaq. EPSS estimates a 2.12% chance of exploitation in the next 30 days, higher than 81.7% of scored vulnerabilities.

Timeline

1. 15-05-2026
   PublishedVulnerability first disclosed.
2. 28-05-2026
   Last modifiedVulnerability information updated.

Description

phpMyFAQ before 4.1.2 contains an unauthenticated SQL injection vulnerability in BuiltinCaptcha::garbageCollector() and BuiltinCaptcha::saveCaptcha() methods that interpolate unsanitized User-Agent headers into DELETE and INSERT queries. Unauthenticated attackers can exploit the public GET /api/captcha endpoint by crafting malicious User-Agent headers to perform time-based blind SQL injection, extracting sensitive data including user credentials, admin tokens, and SMTP credentials from the database.

• CWE-89Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')The product constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component. Without sufficient removal or quoting of SQL syntax in user-controllable inputs, the generated SQL query can cause those inputs to be interpreted as SQL instead of ordinary user data.