Vulnerability · CVE-2019-17543
LZ4 before 1.9.2 has a heap-based buffer overflow in LZ4_write32 (related to LZ4_compress_destSize), affecting applications that call LZ4_compress_fast with a large input.
Published Oct 14, 2019 · catalog updated Oct 14, 2026 · lz4 project
Check if you run it
No confirmed exploitation is on record for CVE-2019-17543. EPSS is 9.12%. Act only if a listed version of lz4 project is installed.
Gaps on this record
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- High8.1
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 9.12%
- Remediation
- Advisory link
- Affected products
- cpe lz4 project/lz4
LZ4 before 1.9.2 has a heap-based buffer overflow in LZ4_write32 (related to LZ4_compress_destSize), affecting applications that call LZ4_compress_fast with a large input. (This issue can also lead to data corruption.) NOTE: the vendor states "only a few specific / uncommon usages of the API are at risk."
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe lz4 project/lz4version unspecified
How to fix CVE-2019-17543
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2019-17543. EPSS is 9.12%. Act only if a listed version of lz4 project is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-787: Out-of-bounds Write. EPSS 9.12%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Oct 14, 2019 · NIST NVD
Detected
LZ4 before 1.9.2 has a heap-based buffer overflow in LZ4_write32 (related to LZ4_compress_destSize), affecting applications that call LZ4_compress_fast with a large input. (This issue can also lead to data corruption.) NOTE: the vendor states "only a few specific / uncommon usages of the API are at risk."
Oct 14, 2026 · NIST NVD
Updated
LZ4 before 1.9.2 has a heap-based buffer overflow in LZ4_write32 (related to LZ4_compress_destSize), affecting applications that call LZ4_compress_fast with a large input. (This issue can also lead to data corruption.) NOTE: the vendor states "only a few specific / uncommon usages of the API are at risk."
Sources
- CVE.orgVulnerability recordCVE-2019-17543
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2019-17543
30-day exploitation probability 9.1%
first.org - NIST NVDVulnerability recordCVE-2019-17543
LZ4 before 1.9.2 has a heap-based buffer overflow in LZ4_write32 (related to LZ4_compress_destSize), affecting applications that call LZ4_compress_fast with a large input. (This issue can also lead to data corruption.) NOTE: the vendor states "only a few specific / uncommon usage
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 16, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.