Native heap corruption via post-close stream setters
Published Sep 9, 2026 · Updated Sep 9, 2026
Use-after-free in Luben zstd-jni 1.3.8-4 through 1.5.7-13 allows local users to corrupt native heap objects or crash the JVM. The stream classes free their native contexts in close() but retain numeric handles, while setDict, setLongMax, setLevel, and setRefMultipleDDicts omit closed-state checks. Exploitation requires code in the hosting JVM to invoke a listed setter on a closed stream; allocator reuse can redirect the write into an unrelated live context.
Summary
What happened
Use-after-free in Luben zstd-jni 1.3.8-4 through 1.5.7-13 allows local users to corrupt native heap objects or crash the JVM. The stream classes free their native contexts in close() but retain numeric handles, while setDict, setLongMax, setLevel, and setRefMultipleDDicts omit closed-state checks. Exploitation requires code in the hosting JVM to invoke a listed setter on a closed stream; allocator reuse can redirect the write into an unrelated live context.
The record
- CVE
- CVE-2026-87877
- Published
- Sep 9, 2026
- Updated
- Sep 9, 2026
- Vendor
- Luben
- Product
- zstd-jni
- Classifications
- CWE-416
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 9, 2026CVE publishedPublication date reported by the CVE source.
- Sep 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.3.8-4 <1.5.7-14
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GHSA deterministic reproduction harnessproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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