CVE-2026-54736
HighCVSS 8.2Exploitation Probability (EPSS)
Low risk4th percentile - higher than 4% of all known CVEs
Summary
A vulnerability in Phalcon before version 5.14.1 allows an attacker to exploit a timing side-channel in the Phalcon\Encryption\Crypt::decrypt function, where the HMAC comparison is performed byte-by-byte and returns early on the first mismatch. This enables the attacker to recover a valid HMAC tag byte-by-byte and attach it to a chosen IV and ciphertext, causing decrypt() to accept tampered encrypted content as authentic.
Risk Assessment
The risk is that an attacker can perform a timing attack to bypass integrity verification, potentially accepting forged or modified encrypted data as authentic, which could lead to data manipulation or privilege escalation.
Recommendation
Immediately update Phalcon to version 5.14.1 or later, which fixes the timing side-channel vulnerability in HMAC comparison.
Other vulnerabilities in Phalcon
See all- CVE-2026-59989Critical
Phalcon is a high-performance, full-stack PHP framework. In 5.15.0 and earlier, resolveFilter in phalcon/Mvc/View/Engine/Volt/Compiler.zep builds the join filter by inserting the raw separator and array token values into generated PHP without passing them through expression(). An attacker who can influence Volt template source can place quote-breaking content in a join argument, inject PHP into the compiled cache file, and execute it when Phalcon\Mvc\View\Engine\Volt::render() loads the template. This issue is fixed in version 5.16.0.
- CVE-2026-57584High
A vulnerability in Phalcon before version 5.15.0 causes the default MVC router to use a compiled PCRE pattern with a nested quantifier, allowing an attacker to trigger catastrophic backtracking via a crafted request URI containing repeated slashes and newline characters. This leads to CPU exhaustion or route-matching failure.
Original NVD description (English source)
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.