CVE-2021-32628

Vulnerability in handling large ziplists

HIGH
7.5
CVSS Score
Published: October 4, 2021 at 05:35 PM UTC
Updated: June 17, 2026 at 03:53 AM UTC
6 products affected across 5 vendorsDebian LinuxFedoraRedis

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Severity
HIGH7.5
Exploit prediction
EPSS 14%

Description

Redis is an open source, in-memory database that persists on disk. An integer overflow bug in the ziplist data structure used by all versions of Redis can be exploited to corrupt the heap and potentially result with remote code execution. The vulnerability involves modifying the default ziplist configuration parameters (hash-max-ziplist-entries, hash-max-ziplist-value, zset-max-ziplist-entries or zset-max-ziplist-value) to a very large value, and then constructing specially crafted commands to create very large ziplists. The problem is fixed in Redis versions 6.2.6, 6.0.16, 5.0.14. An additional workaround to mitigate the problem without patching the redis-server executable is to prevent users from modifying the above configuration parameters. This can be done using ACL to restrict unprivileged users from using the CONFIG SET command.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 5.0.14v < 6.0.16v < 6.2.65.0.0 ≤ v < 5.0.146.0.0 ≤ v < 6.0.166.2.0 ≤ v < 6.2.6
Affected range stops below 5.0.14, so it looks safe — our inference, not a vendor statement
Affected range stops below 6.0.16, so it looks safe — our inference, not a vendor statement
Affected range stops below 6.2.6, so it looks safe — our inference, not a vendor statement

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-190CWE-680

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