CVE-2026-54736 — Phalcon: Non-constant-time HMAC verification in `Encryption\Crypt::decrypt` (timing side-channel)
Phalcon is a high-performance, full-stack PHP framework. Prior to 5.14.1, Phalcon\Encryption\Crypt::decrypt compares the attacker-supplied HMAC tag against the freshly computed …
Published: 2026-07-10 · CVSS: 8.2 · CVSS 4.0
Phalcon is a high-performance, full-stack PHP framework. Prior to 5.14.1, Phalcon\Encryption\Crypt::decrypt compares the attacker-supplied HMAC tag against the freshly computed HMAC using PHP/Zephir identity comparison, which lowers to a byte-wise comparison that returns early on the first differing byte. This observable timing discrepancy can allow an attacker to recover a valid tag byte-by-byte and attach it to a chosen IV and ciphertext so that decrypt() accepts tampered encrypted content as authentic. This issue is fixed in version 5.14.1.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7