CVE-2026-54736CWE-208CWE-347

Phalcon: Non-constant-time HMAC verification in `Encryption\Crypt::decrypt` (timing side-channel)

High · published July 10, 2026

CVSS v4.0
8.2
EPSS
0%
Percentile
7.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
8.2 · HIGH
Vector
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
EPSS
0.00180 · 7.2th percentile
Weaknesses
CWE-208 · Observable Timing Discrepancy; CWE-347 · Improper Verification of Cryptographic Signature
Published
2026-07-10T21:02Z
EPSS history
Timeline
  • 10 JUL 21:02Z
    Phalcon: Non-constant-time HMAC verification in `Encryption\Crypt::decrypt` (timing side-channel)
    cvelistv5