CVE Catalog

CVE-2026-42155

CriticalCVSS 9.3
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.30%

23th percentile - higher than 23% of all known CVEs

Summary

In Magento LTS prior to 20.18.0, the XML-RPC/SOAP API session ID is generated using an outdated time-based construction (MD5 of time-derived values and PHP LCG state) instead of a CSPRNG. The severely constrained entropy allows an attacker to perform a high-speed online brute-force attack and hijack active API sessions.

Risk Assessment

Session hijacking can lead to unauthorized access to e-commerce data and functions, resulting in customer data leakage or order manipulation.

Recommendation

Upgrade Magento LTS to version 20.18.0 or later. Additionally, implement rate limiting on API endpoints to hinder brute-force attacks.

Related vulnerabilities

Original NVD description (English source)

Magento Long Term Support (LTS) is an unofficial, community-driven project provides an alternative to the Magento Community Edition e-commerce platform with a high level of backward compatibility. Prior to 20.18.0, the XML-RPC / SOAP API session ID is generated using an outdated, time-based construction rather than a Cryptographically Secure Pseudo-Random Number Generator (CSPRNG). All inputs to the MD5 hash are time-derived and non-secure. Because the resulting digest relies entirely on the timestamp and the PHP internal LCG state, the effective entropy is severely constrained. This violates the OWASP ASVS v4 requirement of ≥ 64 bits of entropy (V3.2.2) and NIST SP 800-63B standards. By narrowing the LCG window (via server state leaks or general predictability) and leveraging the lack of API rate-limiting, an attacker can generate a localized pool of candidate MD5 hashes and execute a high-speed online brute-force attack to hijack active API sessions. This vulnerability is fixed in 20.18.0.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS