# CVE-2019-17543: lz4: The lz4 packages provide support for LZ4, a very fast, lossless compression algorithm that provides compression speed...

CVE-2019-17543 is fixed in 3 products on 1 platform, first by ELSA-2025-11035, released July 14, 2025. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2019-17543
- Priority: High
- CVSS: 8.1 (Moderate)
- EPSS: 0.1045
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 14, 2025

## Description

The lz4 packages provide support for LZ4, a very fast, lossless compression algorithm that provides compression speeds of 400 MB/s per core and scales with multicore CPUs. It also features an extremely fast decoder that reaches speeds of multiple GB/s per core and typically reaches RAM speed limits on multicore systems.  Security Fix(es):  * lz4: heap-based buffer overflow in LZ4_write32 (CVE-2019-17543)  For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | lz4 RHEL 8 | 0:1.8.3-5.el8_10 | [RHSA-2025:11035](https://patchblox.com/security/data/fix/linux/rhsa-2025-11035.md) | Jul 15, 2025 |
| Linux | lz4 almalinux 8 | 1.8.3-5.el8_10 | [ALSA-2025:11035](https://patchblox.com/security/data/fix/linux/alsa-2025-11035.md) | Jul 15, 2025 |
| Linux | lz4 ol 8 | 0:1.8.3-5.el8_10 | [ELSA-2025-11035](https://patchblox.com/security/data/fix/linux/elsa-2025-11035.md) | Jul 14, 2025 |
| Linux | lz4 rocky 8 | 0:1.8.3-5.el8_10 | [RLSA-2025:11035](https://patchblox.com/security/data/fix/linux/rlsa-2025-11035.md) | Jul 29, 2025 |
| Linux | lz4-devel RHEL 8 | 0:1.8.3-5.el8_10 | [RHSA-2025:11035](https://patchblox.com/security/data/fix/linux/rhsa-2025-11035.md) | Jul 15, 2025 |
| Linux | lz4-devel almalinux 8 | 1.8.3-5.el8_10 | [ALSA-2025:11035](https://patchblox.com/security/data/fix/linux/alsa-2025-11035.md) | Jul 15, 2025 |
| Linux | lz4-devel ol 8 | 0:1.8.3-5.el8_10 | [ELSA-2025-11035](https://patchblox.com/security/data/fix/linux/elsa-2025-11035.md) | Jul 14, 2025 |
| Linux | lz4-libs RHEL 8 | 0:1.8.3-5.el8_10 | [RHSA-2025:11035](https://patchblox.com/security/data/fix/linux/rhsa-2025-11035.md) | Jul 15, 2025 |
| Linux | lz4-libs almalinux 8 | 1.8.3-5.el8_10 | [ALSA-2025:11035](https://patchblox.com/security/data/fix/linux/alsa-2025-11035.md) | Jul 15, 2025 |
| Linux | lz4-libs ol 8 | 0:1.8.3-5.el8_10 | [ELSA-2025-11035](https://patchblox.com/security/data/fix/linux/elsa-2025-11035.md) | Jul 14, 2025 |

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Data as of 2026-11-07T06:34:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo