CVE-2026-42207: Magento LTS: Open Redirect via Unvalidated `uenc` Parameter in `stockAction()` - magento-lts

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-15 · updated 2026-10-26
Weakness: CWE-601

Description

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, Mage_ProductAlert_AddController::stockAction() reads the uenc query parameter and passes it directly to $this->_redirectUrl($backUrl) without calling $this->_isUrlInternal(). When the supplied product_id does not match any catalog product, the server issues an unvalidated HTTP 302 redirect to whatever URL was provided as uenc. This vulnerability is fixed in 20.18.0.

Affected products

OpenMage magento-lts: before 20.18.0

References

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