CVE-2026-87877

zstd-jni versions before 1.5.7-14 fail to validate closed state in setDict, setLongMax, setLevel and setRefMultipleDDicts methods of stream classes. Attackers can call these methods on closed streams to write through freed native pointers, corrupting unrelated objects or crashing the JVM.

  • Published Sep 9, 2026
  • CVSS 7.0 high
  • 0.2% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

CVE-2026-87877 at the National Vulnerability Database