Quick answers
- Is CVE-2026-87824 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-87824 being exploited in the wild.
- How severe is CVE-2026-87824?
- High severity, with a CVSS score of 7.5, published 9 September 2026.
- Which products and versions are affected?
- Luben Zstd-Jni before 1.5.7-14.
- Is there a fix for CVE-2026-87824?
- A patch was published on 2026-08-16: Version 1.5.7-14 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-87824 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-87824?
- Check whether you run Luben Zstd-Jni at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability is a classic out-of-bounds memory read flaw in the native implementation of Zstd.trainFromBufferDirect. The method accepts an array of per-sample lengths but fails to properly validate that these lengths do not cause buffer reads past the allocated sample buffer capacity. An attacker can supply crafted sample length values that cause the underlying native code to walk past buffer boundaries during the training operation. The attack is network-adjacent or local, depending on how the application exposes the trainFromBufferDirect API. Successful exploitation results in JVM termination. The fix is available in version 1.5.7-14 and later.
Affected products
- luben zstd-jni before 1.5.7-14
Timeline
- 2026-09-09: disclosed
- 2026-08-16: patched: Version 1.5.7-14 released