CVE catalog

CVE-2021-3520

lz4: CVE-2021-3520

Severity: Critical · CVSS 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C
Published: Apr 28, 2021, 12:00:00 AM UTC
Source: [NVD] · [CVE record]
EPSS: 3.40% · Oct 25, 2026

There's a flaw in lz4. An attacker who submits a crafted file to an application linked with lz4 may be able to trigger an integer overflow, leading to calling of memmove() on a negative size argument, causing an out-of-bounds write and/or a crash. The greatest impact of this flaw is to availability, with some potential impact to confidentiality and integrity as well.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	lz4	sid	`1.10.0-10`	fixed
Debian	lz4	forky	`1.10.0-10`	fixed
Debian	lz4	trixie	`1.10.0-4`	fixed
Debian	lz4	bookworm	`1.9.4-1`	fixed
Cpe	lz4	Not reported	`1.9.4`	fixed
Cpe	active_iq_unified_manager	Not reported	Not reported	unknown
Cpe	cloud_backup	Not reported	Not reported	unknown
Cpe	ontap_select_deploy_administration_utility	Not reported	Not reported	unknown
Cpe	communications_cloud_native_core_policy	Not reported	Not reported	unknown
Cpe	zfs_storage_appliance_kit	Not reported	Not reported	unknown
Cpe	universal_forwarder	Not reported	Not reported	unknown
Alpine	lz4	3.12	`1.9.2-r1`	fixed
Alpine	lz4	3.13	`1.9.2-r1`	fixed
Alpine	lz4	3.14	`1.9.3-r1`	fixed
Alpine	lz4	3.15	`1.9.3-r1`	fixed
Alpine	lz4	3.16	`1.9.3-r1`	fixed
Alpine	lz4	3.17	`1.9.3-r1`	fixed
Alpine	lz4	3.18	`1.9.3-r1`	fixed
Alpine	lz4	3.19	`1.9.3-r1`	fixed
Alpine	lz4	3.20	`1.9.3-r1`	fixed
Alpine	lz4	3.21	`1.9.3-r1`	fixed
Alpine	lz4	3.22	`1.9.3-r1`	fixed
Alpine	lz4	3.23	`1.9.3-r1`	fixed
Alpine	lz4	3.24	`1.9.3-r1`	fixed
Ubuntu	lz4	pro	`0.0~r131-1`	vulnerable
Ubuntu	lz4	pro	`0.0~r131-2`	vulnerable
Ubuntu	lz4	pro	`0.0~r131-2ubuntu2`	vulnerable
Ubuntu	lz4	pro	`0.0~r131-2ubuntu2+esm1`	fixed
Ubuntu	lz4	pro	`0.0~r131-1`	vulnerable
Ubuntu	lz4	pro	`0.0~r131-2`	vulnerable
Ubuntu	lz4	pro	`0.0~r131-2ubuntu2`	vulnerable
Ubuntu	lz4	pro	`0.0~r131-2ubuntu2+esm1`	fixed
Ubuntu	lz4	18.04	`0.0~r131-2ubuntu2`	vulnerable
Ubuntu	lz4	18.04	`0.0~r131-2ubuntu3`	vulnerable
Ubuntu	lz4	18.04	`0.0~r131-2ubuntu3.1`	fixed
Ubuntu	lz4	20.04	`1.9.1-1`	vulnerable
Ubuntu	lz4	20.04	`1.9.1-2`	vulnerable
Ubuntu	lz4	20.04	`1.9.2-2`	vulnerable
Ubuntu	lz4	20.04	`1.9.2-2ubuntu0.20.04.1`	fixed
Ubuntu	lz4	18.04	`0.0~r131-2ubuntu2`	vulnerable
Ubuntu	lz4	18.04	`0.0~r131-2ubuntu3`	vulnerable
Ubuntu	lz4	18.04	`0.0~r131-2ubuntu3.1`	fixed
Ubuntu	lz4	20.04	`1.9.1-1`	vulnerable
Ubuntu	lz4	20.04	`1.9.1-2`	vulnerable
Ubuntu	lz4	20.04	`1.9.2-2`	vulnerable
Ubuntu	lz4	20.04	`1.9.2-2ubuntu0.20.04.1`	fixed
Opensuse	lz4	tumbleweed	`1.9.3-2.1`	fixed
Opensuse	lz4	leap 15.2	`1.8.0-lp152.5.3.1`	fixed
Opensuse	lz4-test	leap 15.2	`1.8.0-lp152.5.3.1`	fixed
Suse	lz4	linux enterprise module for basesystem 15 sp3	`1.9.2-3.3.1`	fixed
Opensuse	lz4	leap 15.3	`1.9.2-3.3.1`	fixed
Suse	lz4	linux enterprise module for basesystem 15 sp2	`1.8.0-3.8.1`	fixed
Suse	lz4	linux enterprise high performance computing 15-espos	`1.8.0-3.8.1`	fixed
Suse	lz4	linux enterprise high performance computing 15-ltss	`1.8.0-3.8.1`	fixed
Suse	lz4	linux enterprise high performance computing 15 sp1-espos	`1.8.0-3.8.1`	fixed
Suse	lz4	linux enterprise high performance computing 15 sp1-ltss	`1.8.0-3.8.1`	fixed
Suse	lz4	linux enterprise server 15-ltss	`1.8.0-3.8.1`	fixed
Suse	lz4	linux enterprise server 15 sp1-bcl	`1.8.0-3.8.1`	fixed
Suse	lz4	linux enterprise server 15 sp1-ltss	`1.8.0-3.8.1`	fixed
Suse	lz4	linux enterprise server for sap applications 15	`1.8.0-3.8.1`	fixed
Suse	lz4	linux enterprise server for sap applications 15 sp1	`1.8.0-3.8.1`	fixed
Suse	lz4	manager proxy 4.0	`1.8.0-3.8.1`	fixed
Suse	lz4	manager retail branch server 4.0	`1.8.0-3.8.1`	fixed
Suse	lz4	manager server 4.0	`1.8.0-3.8.1`	fixed
Suse	lz4	linux enterprise micro 5.0	`1.8.0-3.8.1`	fixed
Suse	lz4	enterprise storage 6	`1.8.0-3.8.1`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	lz4	source	sid	`1.9.3-2`	not yet assigned	Not reported	[987856]
Debian	lz4	source	forky	`1.9.3-2`	not yet assigned	Not reported	[987856]
Debian	lz4	source	trixie	`1.9.3-2`	not yet assigned	Not reported	[987856]
Debian	lz4	source	bookworm	`1.9.3-2`	not yet assigned	Not reported	[987856]
Cpe	lz4	cpe	Not reported	`1.9.4`	Not reported	NVD-CVE-2021-3520	Not reported
Alpine	lz4	apk	3.12	`1.9.2-r1`	Not reported	ALPINE-CVE-2021-3520	Not reported
Alpine	lz4	apk	3.13	`1.9.2-r1`	Not reported	ALPINE-CVE-2021-3520	Not reported
Alpine	lz4	apk	3.14	`1.9.3-r1`	Not reported	ALPINE-CVE-2021-3520	Not reported
Alpine	lz4	apk	3.15	`1.9.3-r1`	Not reported	ALPINE-CVE-2021-3520	Not reported
Alpine	lz4	apk	3.16	`1.9.3-r1`	Not reported	ALPINE-CVE-2021-3520	Not reported
Alpine	lz4	apk	3.17	`1.9.3-r1`	Not reported	ALPINE-CVE-2021-3520	Not reported
Alpine	lz4	apk	3.18	`1.9.3-r1`	Not reported	ALPINE-CVE-2021-3520	Not reported
Alpine	lz4	apk	3.19	`1.9.3-r1`	Not reported	ALPINE-CVE-2021-3520	Not reported
Alpine	lz4	apk	3.20	`1.9.3-r1`	Not reported	ALPINE-CVE-2021-3520	Not reported
Alpine	lz4	apk	3.21	`1.9.3-r1`	Not reported	ALPINE-CVE-2021-3520	Not reported
Alpine	lz4	apk	3.22	`1.9.3-r1`	Not reported	ALPINE-CVE-2021-3520	Not reported
Alpine	lz4	apk	3.23	`1.9.3-r1`	Not reported	ALPINE-CVE-2021-3520	Not reported
Alpine	lz4	apk	3.24	`1.9.3-r1`	Not reported	ALPINE-CVE-2021-3520	Not reported
Ubuntu	lz4	deb	pro	`0.0~r131-2ubuntu2+esm1`	Not reported	USN-4968-2	Not reported
Ubuntu	lz4	deb	pro	`0.0~r131-2ubuntu2+esm1`	Not reported	UBUNTU-CVE-2021-3520	Not reported
Ubuntu	lz4	deb	18.04	`0.0~r131-2ubuntu3.1`	Not reported	UBUNTU-CVE-2021-3520	Not reported
Ubuntu	lz4	deb	20.04	`1.9.2-2ubuntu0.20.04.1`	Not reported	UBUNTU-CVE-2021-3520	Not reported
Ubuntu	lz4	deb	18.04	`0.0~r131-2ubuntu3.1`	Not reported	USN-4968-1	Not reported
Ubuntu	lz4	deb	20.04	`1.9.2-2ubuntu0.20.04.1`	Not reported	USN-4968-1	Not reported
Opensuse	lz4	rpm	tumbleweed	`1.9.3-2.1`	Not reported	OPENSUSE-SU-2024:11562-1	Not reported
Opensuse	lz4	rpm	leap 15.2	`1.8.0-lp152.5.3.1`	Not reported	OPENSUSE-SU-2021:0760-1	Not reported
Opensuse	lz4-test	rpm	leap 15.2	`1.8.0-lp152.5.3.1`	Not reported	OPENSUSE-SU-2021:0760-1	Not reported
Suse	lz4	rpm	linux enterprise module for basesystem 15 sp3	`1.9.2-3.3.1`	Not reported	SUSE-SU-2021:1825-1	Not reported
Opensuse	lz4	rpm	leap 15.3	`1.9.2-3.3.1`	Not reported	OPENSUSE-SU-2021:1825-1	Not reported
Suse	lz4	rpm	linux enterprise module for basesystem 15 sp2	`1.8.0-3.8.1`	Not reported	SUSE-SU-2021:1647-1	Not reported
Suse	lz4	rpm	linux enterprise high performance computing 15-espos	`1.8.0-3.8.1`	Not reported	SUSE-SU-2021:1647-1	Not reported
Suse	lz4	rpm	linux enterprise high performance computing 15-ltss	`1.8.0-3.8.1`	Not reported	SUSE-SU-2021:1647-1	Not reported
Suse	lz4	rpm	linux enterprise high performance computing 15 sp1-espos	`1.8.0-3.8.1`	Not reported	SUSE-SU-2021:1647-1	Not reported
Suse	lz4	rpm	linux enterprise high performance computing 15 sp1-ltss	`1.8.0-3.8.1`	Not reported	SUSE-SU-2021:1647-1	Not reported
Suse	lz4	rpm	linux enterprise server 15-ltss	`1.8.0-3.8.1`	Not reported	SUSE-SU-2021:1647-1	Not reported
Suse	lz4	rpm	linux enterprise server 15 sp1-bcl	`1.8.0-3.8.1`	Not reported	SUSE-SU-2021:1647-1	Not reported
Suse	lz4	rpm	linux enterprise server 15 sp1-ltss	`1.8.0-3.8.1`	Not reported	SUSE-SU-2021:1647-1	Not reported
Suse	lz4	rpm	linux enterprise server for sap applications 15	`1.8.0-3.8.1`	Not reported	SUSE-SU-2021:1647-1	Not reported
Suse	lz4	rpm	linux enterprise server for sap applications 15 sp1	`1.8.0-3.8.1`	Not reported	SUSE-SU-2021:1647-1	Not reported
Suse	lz4	rpm	manager proxy 4.0	`1.8.0-3.8.1`	Not reported	SUSE-SU-2021:1647-1	Not reported
Suse	lz4	rpm	manager retail branch server 4.0	`1.8.0-3.8.1`	Not reported	SUSE-SU-2021:1647-1	Not reported
Suse	lz4	rpm	manager server 4.0	`1.8.0-3.8.1`	Not reported	SUSE-SU-2021:1647-1	Not reported
Suse	lz4	rpm	linux enterprise micro 5.0	`1.8.0-3.8.1`	Not reported	SUSE-SU-2021:1647-1	Not reported
Suse	lz4	rpm	enterprise storage 6	`1.8.0-3.8.1`	Not reported	SUSE-SU-2021:1647-1	Not reported

[Debian bug #987856]

OpenFactory catalog packages

[openSUSE Tumbleweed]

[liblz4-1]Unknown
Source package: [lz4]
Details (1)
- 1.10.0-2.8 · x86_64 · tumbleweed
  Unknown · Fixed: 1.9.3-2.1
  Version impact unknown
  dsa · lz4 · opensuse · tumbleweed
[liblz4-1-32bit]Unknown
Source package: [lz4]
Details (1)
- 1.10.0-2.8 · x86_64 · tumbleweed
  Unknown · Fixed: 1.9.3-2.1
  Version impact unknown
  dsa · lz4 · opensuse · tumbleweed
[liblz4-1-x86-64-v3]Unknown
Source package: [lz4]
Details (1)
- 1.10.0-2.8 · x86_64 · tumbleweed
  Unknown · Fixed: 1.9.3-2.1
  Version impact unknown
  dsa · lz4 · opensuse · tumbleweed
[liblz4-devel]Unknown
Source package: [lz4]
Details (1)
- 1.10.0-2.8 · x86_64 · tumbleweed
  Unknown · Fixed: 1.9.3-2.1
  Version impact unknown
  dsa · lz4 · opensuse · tumbleweed
[lz4]Fixed
Source package: [lz4]
Details (1)
- 1.10.0-2.8 · x86_64 · tumbleweed
  Fixed · Fixed: 1.9.3-2.1
  dsa · lz4 · opensuse · tumbleweed

[Debian 12 (Bookworm)]

[liblz4-1]Fixed
Source package: [lz4]
Details (2)
- 1.9.4-1 · amd64 · bookworm
  Fixed · Fixed: 1.9.3-2
  dsa · lz4 · debian · bookworm
- 1.9.4-1 · arm64 · bookworm
  Fixed · Fixed: 1.9.3-2
  dsa · lz4 · debian · bookworm
[liblz4-dev]Fixed
Source package: [lz4]
Details (2)
- 1.9.4-1 · amd64 · bookworm
  Fixed · Fixed: 1.9.3-2
  dsa · lz4 · debian · bookworm
- 1.9.4-1 · arm64 · bookworm
  Fixed · Fixed: 1.9.3-2
  dsa · lz4 · debian · bookworm
[liblz4-tool]Fixed
Source package: [lz4]
Details (2)
- 1.9.4-1 · all · bookworm
  Fixed · Fixed: 1.9.3-2
  dsa · lz4 · debian · bookworm
- 1.9.4-1 · all · bookworm
  Fixed · Fixed: 1.9.3-2
  dsa · lz4 · debian · bookworm
[lz4]Fixed
Details (2)
- 1.9.4-1 · amd64 · bookworm
  Fixed · Fixed: 1.9.3-2
  dsa · lz4 · debian · bookworm
- 1.9.4-1 · arm64 · bookworm
  Fixed · Fixed: 1.9.3-2
  dsa · lz4 · debian · bookworm

Observed: Oct 23, 2026, 5:58:28 PM UTC

References

[CERT-Bund public advisories] · [CISA cybersecurity advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]