CVE-2021-21426: Fixes a bug in Zend Framework's Stream HTTP Wrapper

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-04-21 · updated 2026-06-17
Weakness: CWE-502

Description

Magento-lts is a long-term support alternative to Magento Community Edition (CE). In magento-lts versions 19.4.12 and prior and 20.0.8 and prior, there is a vulnerability caused by the unsecured deserialization of an object. A patch in versions 19.4.13 and 20.0.9 was back ported from Zend Framework 3. The vulnerability was assigned CVE-2021-3007 in Zend Framework.

Affected products

OpenMage magento-lts: before 19.4.13; from 20.0.0 before 20.0.9 — fixed in 19.4.13, 20.0.9

How to fix

Upgrade to a fixed version: OpenMage magento-lts 19.4.13, 20.0.9. Check the vendor advisory for mitigations.

References

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