CVE-2026-87824

A flaw was found in zstd-jni. Attackers can exploit this by supplying oversized per-sample lengths to the Zstd.trainFromBufferDirect function, which fails to validate the samples buffer capacity. This allows for reading past buffer boundaries, leading to out-of-bounds memory access and ultimately causing the Java Virtual Machine (JVM) to terminate, resulting in a Denial of Service (DoS).

Red Hat has determined that CVE-2026-87824 affects Red Hat products that include the zstd-jni library in a vulnerable version. The vulnerability can allow a remote attacker to terminate the Java Virtual Machine by supplying crafted sample lengths to the dictionary-training function.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

No complete workaround is currently available. As a temporary measure, applications using Zstd.trainFromBufferDirect() should validate that all sample lengths are non-negative and that their total does not exceed the capacity of the samples buffer before calling the function. Avoid passing attacker-controlled sample length arrays to this function until an update is available. Upgrade to a Red Hat product release containing zstd-jni 1.5.7-14 or later when available.