CVE-2026-87823Public exploit

JVM crash via overflowing native bounds checks

Published Sep 9, 2026 · Updated Sep 9, 2026

Out-of-bounds reads in Luben zstd-jni 1.1.1 through 1.5.7-13 allow attackers to crash a JVM through crafted buffer offsets. Three direct-ByteBuffer frame-size native methods add or subtract signed 32-bit offsets and sizes without first rejecting negative values, allowing checks to wrap or pass before pointer arithmetic. Reachability requires a consuming application to pass attacker-influenced values to these public native methods; only JVM termination was demonstrated.

CVSS severity8.8
High
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds reads in Luben zstd-jni 1.1.1 through 1.5.7-13 allow attackers to crash a JVM through crafted buffer offsets. Three direct-ByteBuffer frame-size native methods add or subtract signed 32-bit offsets and sizes without first rejecting negative values, allowing checks to wrap or pass before pointer arithmetic. Reachability requires a consuming application to pass attacker-influenced values to these public native methods; only JVM termination was demonstrated.

The record

CVE
CVE-2026-87823
Published
Sep 9, 2026
Updated
Sep 9, 2026
Vendor
Luben
Product
zstd-jni
Classifications
CWE-125, CWE-190
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 9, 2026CVE publishedPublication date reported by the CVE source.
  2. 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.

  1. Affected versionversion=1.1.1 <1.5.7-14

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Luben · zstd-jniversion=1.1.1 <1.5.7-14

Published CVSS scores

5.7GitHub Security AdvisoryCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H
8.8VulnCheck CNACVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
8.2VulnCheck CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
CWE-190Integer Overflow or Wraparound

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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