CVE-2021-3696: GNU GRUB2

Medium severity, CVSS 4.5. EPSS: 0.5% chance of exploitation in the next 30 days.

A heap out-of-bounds write may heppen during the handling of Huffman tables in the PNG reader. This may lead to data corruption in the heap space. Confidentiality, Integrity and Availablity impact may be considered Low as it's very complex to an attacker control the encoding and positioning of corrupted Huffman entries to achieve results such as arbitrary code execution and/or secure boot circumvention. This flaw affects grub2 versions prior grub-2.12.

Affected products

• GNU GRUB2: from 2.00, before 2.12 (fixed in 2.12)
• Netapp Ontap Select Deploy Administration Utility: affected versions not specified
• Red Hat Codeready Linux Builder: affected versions not specified
• Red Hat Developer Tools: version 1.0 only
• Red Hat Enterprise Linux: version 8.0 only; version 8.1 only; version 8.4 only; version 9.0 only
• Red Hat Enterprise Linux Eus: version 8.2 only; version 8.4 only; version 8.6 only; version 9.0 only
• Red Hat Enterprise Linux For Power Little Endian: version 8.0 only; version 9.0 only
• Red Hat Enterprise Linux For Power Little Endian Eus: version 8.2 only; version 8.4 only; version 8.6 only; version 9.0 only
• Red Hat Enterprise Linux Server Aus: version 8.2 only; version 8.4 only; version 8.6 only
• Red Hat Enterprise Linux Server For Power Little Endian Update Services For SAP Solutions: version 8.1 only; version 8.2 only; version 8.4 only; version 8.6 only; version 9.0 only
• Red Hat Enterprise Linux Server Tus: version 8.2 only; version 8.4 only; version 8.6 only
• Red Hat Openshift: version 3.0 only
• Red Hat Openshift Container Platform: version 4.6 only; version 4.9 only; version 4.10 only

Published 2022-07-06. Last modified 2026-06-17.