Disclosure summary
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.
Source-reported weakness categories
CWE-190, CWE-787
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
NIST NVD · NVD-CVE-2021-3520
Open original source · Updated Oct 08, 2026
Only CPE matches marked vulnerable=true are indexed. AND/OR platform conditions must be checked in the original NVD record.
| Vendor | Product / association | Version / bounds |
|---|---|---|
| lz4_project | lz4 | * · versionStartIncluding: 1.8.3 · versionEndExcluding: 1.9.4 |
| netapp | active_iq_unified_manager | - |
| netapp | cloud_backup | - |
| netapp | ontap_select_deploy_administration_utility | - |
| oracle | communications_cloud_native_core_policy | 1.14.0 |
| oracle | zfs_storage_appliance_kit | 8.8 |
| splunk | universal_forwarder | * · versionStartIncluding: 9.0.0 · versionEndExcluding: 9.0.6 |
| splunk | universal_forwarder | 9.1.0 |
NIST NVD · nvd:CVE-2021-3520
Open original source · Updated Oct 08, 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.
Source severity: CRITICAL / 9.8
Indexed product associations
These cached associations support search and triage. Confirm applicability, platform conditions, and fixed versions in the original record.
| Vendor | Product | Version | Source / relationship |
|---|---|---|---|
| lz4 project | lz4 | * | nvd / vulnerable |
| netapp | active iq unified manager | - | nvd / vulnerable |
| netapp | cloud backup | - | nvd / vulnerable |
| netapp | ontap select deploy administration utility | - | nvd / vulnerable |
| oracle | communications cloud native core policy | 1.14.0 | nvd / vulnerable |
| oracle | zfs storage appliance kit | 8.8 | nvd / vulnerable |
| splunk | universal forwarder | * | nvd / vulnerable |
| splunk | universal forwarder | 9.1.0 | nvd / vulnerable |
Original records & references
- NIST NVD record
- CVE Program record
- secalert@redhat.com — Issue Tracking, Patch, Third Party Advisory
- secalert@redhat.com — Third Party Advisory
- secalert@redhat.com — Patch, Third Party Advisory
- secalert@redhat.com — Patch, Third Party Advisory
- secalert@redhat.com — Patch, Third Party Advisory
GitHub repository matches
Repository matches are links and GitHub-supplied metadata only. They are not verified working proof-of-concept code. Each supported query is bounded to ten pages and at most 1,000 indexed results. This is not a complete index of GitHub or public exploit research. Coverage can also be limited by provider availability, rate limits, rejected metadata, incomplete search results, manual review, and the recorded refresh time.
No stored repository matches
Repository discovery has not recorded an update for this CVE yet.
Discovery progress
0 of 3 discovery queries finished. GitHub returned 0 indexed results; 0 malformed or disallowed results were rejected.
No discovery update has been recorded for this CVE.
View all 0 stored repository matches
PUBLISHED 2021-06-02T13:15:13+00:00
MODIFIED 2026-10-08T21:17:40+00:00
INGESTED 2026-10-12T06:57:10+00:00