CVE-2026-46364: thorsten/phpmyfaq (Composer (PHP))

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
EPSS 2.1%, percentile 82: FIRST’s model estimates a 2.1% chance of exploitation activity in the next 30 days, higher than 82% of all scored CVEs (elevated). EPSS is a probability, not a verdict.
Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
Only applies if your dependency tree includes thorsten/phpmyfaq (Composer (PHP)) <= 4.1.1, fixed in 4.1.2; phpmyfaq/phpmyfaq (Composer (PHP)) <= 4.1.1, fixed in 4.1.2. Check your lockfile, including transitive dependencies.

What it is

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.

From the GitHub advisory

Summary

BuiltinCaptcha::garbageCollector() and BuiltinCaptcha::saveCaptcha() at phpmyfaq/src/phpMyFAQ/Captcha/BuiltinCaptcha.php:298 and :330 interpolate the User-Agent header and client IP address into DELETE and INSERT queries with sprintf and no escaping. Both methods run on every hit to the public GET /api/captcha endpoint, which requires no authentication. An unauthenticated attacker sets the User-Agent header to a crafted SQL payload and runs SLEEP(), BENCHMARK(), or time-based blind extraction against the database that backs phpMyFAQ. Verified live against 4.2.0-alpha (master at b9f25109): baseline request 147 ms, request with User-Agent: x' OR SLEEP(2) OR 'x 4.09 s (two SLEEP(2) calls, one per vulnerable sink).

Details

phpmyfaq/src/phpMyFAQ/Captcha/BuiltinCaptcha.php:112 populates two private fields from untrusted HTTP input at construction time:

Both fields are then dropped into sprintf() SQL templates without ever touching Database::escape() or a prepared statement.

Weakness type: CWE-89.

Product: thorsten/phpmyfaq (Composer (PHP)) · Assigned by: VulnCheck · Published: 2026-05-15

Affected and fixed versions

Ecosystem	Package	Vulnerable	First fixed
Composer (PHP)	`thorsten/phpmyfaq`	<= 4.1.1	4.1.2
Composer (PHP)	`phpmyfaq/phpmyfaq`	<= 4.1.1	4.1.2

Vendor	Product	Affected versions (per CVE record)
thorsten	phpmyfaq	< 4.1.2

Severity scores

Scored by	CVSS	Score	Vector
VulnCheck	3.1	9.8 Critical	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
VulnCheck	4.0	9.3 Critical	`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`
GitHub	3.1	9.8	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

Attack vector: network (remotely reachable)
Attack complexity: low
Attack requirements: none
Privileges required: none (no login)
User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
CISA SSVC assessment: exploitation none, automatable yes, technical impact total.
FIRST EPSS (model of 2026-10-21): 2.12% probability of exploitation activity in the next 30 days; percentile 82.

Timeline

2026-05-06 — GitHub-reviewed advisory GHSA-289f-fq7w-6q2w published (critical)
2026-05-15 — CVE record published by VulnCheck
2026-05-28 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.