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Fencer Vulns
medium 5.3

CVE-2021-3470 json

A heap overflow issue was found in Redis in versions before 5.0.10, before 6.0.9 and before 6.2.0 when using a heap allocator other than je…

published 2021-03-31 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-26792

cvss
5.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.1%
EPSS 1.1% chance of exploitation in 30 days, percentile 66%
public exploits
0
none known

Summary

A heap overflow issue was found in Redis in versions before 5.0.10, before 6.0.9 and before 6.2.0 when using a heap allocator other than jemalloc or glibc's malloc, leading to potential out of bound write or process crash. Effectively this flaw does not affect the vast majority of users, who use jemalloc or glibc malloc.

Patch / fix

  • redislabs redis 5.0.10, 6.0.9
  • redis Debian 14, Debian 13, Debian 12 5:6.0.9-1

debian advisories DEBIAN-CVE-2021-3470

  • redis Alpine 3.12 5.0.11-r0
  • redis Alpine 3.13 6.0.9-r0
  • redis Alpine 3.24, Alpine 3.23, Alpine 3.22 +8 more 6.2.0-r0

alpine advisories ALPINE-CVE-2021-3470

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • redis CBL-Mariner 2.0 5.0.5-7

azure linux advisories AZL-6852

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-3470 updated cvss 5.3

redis: potential heap overflow when using a heap allocator other than jemalloc or glibc's malloc

  • Red Hat OpenStack Platform 10 (Newton) redis Red Hat OpenStack Platform 13 (Queens) redis
    affected: no fix planned “Will not fix”
  • Red Hat Advanced Cluster Management for Kubernetes 2 search-api, redisgraph-tls Red Hat Ansible Automation Platform 1.2 redis Red Hat Ansible Tower 3 redis Red Hat Enterprise Linux 8 redis Red Hat Enterprise Linux 9 redis Red Hat Software Collections rh-redis5-redis
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.14% chance of exploitation in the next 30 days, higher than 66% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

  • n/a redis

Classification

Weakness
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
  • CWE-787 Out-of-bounds Write
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.