CVE-2026-54736

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

Published Jul 10, 2026 CVSS 4.0 · 8.2 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-8jqh-95g6-7jpj Phalcon: Non-constant-time HMAC verification in `Encryption\Crypt::decrypt` (timing side-channel)
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Phalcon
Phalcon cphalcon
Vendors & Products Phalcon
Phalcon cphalcon
Type Values Removed Values Added
Description 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.
Title Phalcon: Non-constant-time HMAC verification in `Encryption\Crypt::decrypt` (timing side-channel)
Weaknesses CWE-208
CWE-347
References
Metrics cvssV4_0

{'score': 8.2, '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 13, 2026, 6:01 PM
Reserved
Jun 15, 2026, 11:07 PM
Status
Deferred
Published
Jul 10, 2026, 10:16 PM
Modified
Oct 25, 2026, 3:10 PM