Categories
CVE-2026-59949 medium CVSS 6.5

Vulnerability in at.yawk.lz4:lz4-java (CVE-2026-59949)

Summary

Vulnerability in at.yawk.lz4:lz4-java (CVE-2026-59949). Risk of unauthorized operations or information disclosure. Exploitable via off. Mitigation: upgrade to 1.11.1 or later.

Original description

The description as published by the source.

Summary

Insufficient validation of byte array arguments in JNI-based XXHash implementations in lz4-java 1.11.0 and earlier allows callers to crash the JVM by passing an invalid array reference or invalid range to native XXHash methods.

This affects applications where an attacker can influence the byte array object or the off / len arguments passed to affected XXHash APIs. It does not affect the common case where only the contents of a valid byte array are attacker-controlled.

Java-based XXHash implementations are not affected.

Details

The JNI-backed XXHash implementations pass caller-provided byte array arguments to native code. The affected APIs are:

  • XXHashFactory.nativeInstance().hash32().hash(byte[] buf, int off, int len, int seed)
  • XXHashFactory.nativeInstance().hash64().hash(byte[] buf, int off, int len, long seed)
  • XXHashFactory.nativeInstance().newStreamingHash32(seed).update(byte[] bytes, int off, int len)
  • XXHashFactory.nativeInstance().newStreamingHash64(seed).update(byte[] bytes, int off, int len)

Before the fix, the streaming JNI implementations did not validate bytes, off, or len before calling XXHashJNI.XXH32_update / XXHashJNI.XXH64_update. The non-streaming JNI implementations called SafeUtils.checkRange, but SafeUtils.checkRange(byte[], int, int) skipped all array access when len == 0, so a null byte array with a zero length could still reach JNI.

As a result:

  • hash(null, 0, 0, seed) and `update(null,…

Source: GitHub Security Advisories (Global) NVD GitHub Advisory

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2026-59949 has been found in at.yawk.lz4:lz4-java.
Attackers can target a specific entry point like off over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 6.5/10.
What to do: upgrade at.yawk.lz4:lz4-java to 1.11.1 or later.
If unsure, ask your IT team or search "at.yawk.lz4:lz4-java CVE-2026-59949" on the vendor's site.

CVE-2026-59949 (at.yawk.lz4:lz4-java) — CWE-476 / CVSS v3 6.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: off / len / bytes / XXHashJNI.XXH32_update
Patched: 1.11.1 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (CWE-476) exists in at.yawk.lz4:lz4-java. Attackers reach the vulnerable code path via off without authentication.

📍 Affected scope

Check the vendor advisory for the affected versions of at.yawk.lz4:lz4-java. Attack surface: off / len / bytes / XXHashJNI.XXH32_update.

🔥 Severity

Severity: Medium (CVSS 6.5/10). Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 1.11.1.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

  1. 1
    Identify exposure identify
    Audit SBOM/dependencies for affected components.

    資産台帳・SBOM・依存マニフェストで at.yawk.lz4:lz4-java を使っているサービスとバージョンを洗い出す。

  2. 2
    Apply patch patch
    Upgrade at.yawk.lz4:lz4-java to 1.11.1

    ステージング環境で 1.11.1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。

  3. 3
    Post-deployment verification verify
    Confirm patched version is live in production

    パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

maven at.yawk.lz4:lz4-java
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.11.1"}]}]
maven org.lz4:lz4-java
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

References

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