CVE-2026-54736 phalcon CVE debrief

Who should care

Users of Phalcon framework version prior to 5.14.1 who utilize the Crypt::decrypt method for encryption and decryption operations should be aware of this vulnerability and take necessary actions to mitigate it. This includes upgrading to Phalcon version 5.14.1 or later, implementing compensating controls such as additional authentication or integrity checks on decrypted data, and monitoring for suspicious decryption attempts.

Technical summary

Phalcon's Crypt::decrypt method uses a vulnerable approach to compare HMAC tags, allowing an attacker to exploit a timing discrepancy to recover a valid tag. This issue is fixed in version 5.14.1. The vulnerability affects users of Phalcon framework version prior to 5.14.1 who utilize the Crypt::decrypt method for encryption and decryption operations. The attack can be mitigated by upgrading to Phalcon version 5.14.1 or later, implementing compensating controls, and monitoring for suspicious decryption attempts.

Defensive priority

High

Recommended defensive actions

• Upgrade to Phalcon version 5.14.1 or later
• Implement compensating controls such as additional authentication or integrity checks on decrypted data
• Monitor for suspicious decryption attempts
• Review and verify affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record was published on 2026-07-10T22:16:42.970Z and has not been modified since then. The NVD entry is currently 8.2 HIGH. There are several references provided, including official CVE and NVD records, as well as source references from [email protected]. The Phalcon framework's Crypt::decrypt method is vulnerable to a timing attack, allowing an attacker to recover a valid HMAC tag byte-by-byte and attach it to a chosen IV and ciphertext, allowing decrypt() to accept tampered encrypted content as authentic. Users should verify their deployments and plan for updates or mitigations.

Official resources