CVE-2026-42155: Magento Long Term Support (LTS) is an unofficial, community-driven project provides an alternative to the Magento Community Edition e-commerce platform with a…

PriorityP354critical9.3CVSS 4.0

AVNACLATNPRNUINVCHVIHVALSCNSINSANEXCRXIRXARXMAVXMACXMATXMPRXMUIXMVCXMVIXMVAXMSCXMSIXMSAXSXAUXRXVXREXUX

EPSS

0.27%

18.3th percentile

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 Prior to 20.18.0, the XML-RPC / SOAP API session ID is generated using an outdated, time-based construction rather than a Cryptographically Secure Pseudo-Random Number Generator (CSPRNG).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.

Affected

2 ranges

Vendor	Product	Version range	Fixed in
openmage	magento-lts	< 20.18.0	20.18.0
openmage	magento-lts	>= 0 < 20.18.0	20.18.0

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