CVE-2026-59949

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (38th percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 6.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

yawkat LZ4 Java provides LZ4 compression for Java. Prior to 1.11.1, JNI-backed XXHash implementations fail to validate the byte array object and the off and len arguments in XXHashFactory.nativeInstance().hash32().hash(), XXHashFactory.nativeInstance().hash64().hash(), XXHashFactory.nativeInstance().newStreamingHash32().update(), and XXHashFactory.nativeInstance().newStreamingHash64().update(), allowing null arrays or oversized ranges to reach native code, read outside the Java array, and fatally terminate the JVM. This issue is fixed in version 1.11.1.

CVSS v3
6.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
29
EG Risk 29/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity65% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.5%
EPSS %ILE
38th
KEV
Not listed

CISA SSVCTrack at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

July 24, 2026

Last Modified

September 18, 2026

Advisory Details (3)

Auto-updated Aug 18, 2026
Patch available. Sources: github_release, github, github_commit.
githubMentions a patch (unverified)

Native XXHash implementations can crash the JVM when passed invalid byte array ranges · Advisory · yawkat/lz4-java · GitHub

https://github.com/yawkat/lz4-java/security/advisories/GHSA-xx22-p4ch-683r
github_release Patch Available

lz4-java v1.11.1

Patch available: yawkat/lz4-java v1.11.1

https://github.com/yawkat/lz4-java/releases/tag/v1.11.1
github_commit Patch Available

commit dbd86d04b8dd (yawkat/lz4-java)

Patch available: yawkat/lz4-java v1.11.1 (contains commit dbd86d04b8dd)

https://github.com/yawkat/lz4-java/commit/dbd86d04b8dd716e1c2bc626be54189997d910da

Vendor Advisories for CVE-2026-59949(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(5 across 4 ecosystems)
Maven(2)
PackageVulnerable rangeFix by version rangeDependents
at.yawk.lz4:lz4-java1.10.0 ... 1.9.0 (8 versions)
  • every version up to 1.11.1: fixed in 1.11.1
—
org.lz4:lz4-java1.4 ... 1.8.1 (10 versions)
  • every version through 1.8.1: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
lz4-java1.11.2+ds1-1, 1.11.2+ds1-2, 1.11.2+ds1-3, 1.8.0-3, 1.8.0-4
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
lz4-java1.11.2+ds1-1, 1.11.2+ds1-2, 1.11.2+ds1-3, 1.8.0-4
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
lz4-java1.8.0-4
  • every version up to 1.11.2+ds1-1: fixed in 1.11.2+ds1-1
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 40× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-10 20:00 UTCEPSS rescore
  2. 2026-10-09 20:07 UTCEPSS rescore
  3. 2026-10-08 17:13 UTCEPSS rescore
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  8. 2026-10-04 07:43 UTCEG score recompute
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  14. 2026-09-30 15:03 UTCEPSS rescore
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  17. 2026-09-28 04:27 UTCEG score recompute
  18. 2026-09-27 13:48 UTCEPSS rescore
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  20. 2026-09-25 10:08 UTCEG score recompute
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  22. 2026-09-23 22:17 UTCEG score recompute
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  24. 2026-09-22 22:13 UTCEG score recompute
  25. 2026-09-20 20:16 UTCEPSS rescore
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  1. 2026-09-20 01:40 UTCEG score recompute
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  3. 2026-09-18 19:28 UTCEPSS rescore
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  15. 2026-09-11 14:53 UTCEPSS rescore
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  18. 2026-09-09 08:46 UTCEG score recompute
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  21. 2026-09-07 16:01 UTCEPSS rescore
  22. 2026-09-06 19:14 UTCEG score recompute
  23. 2026-09-06 13:47 UTCEPSS rescore
  24. 2026-09-05 19:23 UTCEG score recompute
  25. 2026-09-04 12:51 UTCEG score recompute
  26. 2026-09-04 05:07 UTCEPSS rescore
  27. 2026-09-02 14:12 UTCEPSS rescore
  28. 2026-09-01 23:16 UTCEG score recompute
  29. 2026-09-01 13:54 UTCEPSS rescore
  30. 2026-09-01 04:40 UTCEPSS rescore
  31. 2026-08-31 00:03 UTCEG score recompute
  32. 2026-08-30 19:17 UTCEPSS rescore
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  35. 2026-08-28 21:42 UTCEPSS rescore
  36. 2026-08-27 21:06 UTCEG score recompute
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  40. 2026-08-25 18:47 UTCEG score recompute
  41. 2026-08-25 13:49 UTCEPSS rescore
  42. 2026-08-24 19:03 UTCEG score recompute
  43. 2026-08-23 19:18 UTCEG score recompute
  44. 2026-08-23 00:19 UTCEPSS rescore
  45. 2026-08-22 19:33 UTCEG score recompute
  46. 2026-08-21 23:49 UTCEPSS rescore
  47. 2026-08-21 19:48 UTCEG score recompute
  48. 2026-08-20 22:55 UTCEPSS rescore
  49. 2026-08-19 20:18 UTCEG score recompute
  50. 2026-08-19 17:04 UTCEPSS rescore
  51. 2026-08-18 18:25 UTCEG score recompute
  52. 2026-08-18 18:00 UTCEG score recompute
  53. 2026-08-18 15:34 UTCEG score recompute
  54. 2026-07-31 08:34 UTCEG score recompute
  55. 2026-07-27 09:28 UTCEG score recompute
  56. 2026-07-24 17:13 UTCEG score recompute

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-59949?
CVE-2026-59949 is a medium vulnerability published on July 24, 2026. yawkat LZ4 Java provides LZ4 compression for Java. Prior to 1.11.1, JNI-backed XXHash implementations fail to validate the byte array object and the off and len arguments in XXHashFactory.nativeInstance().hash32().hash(), XXHashFactory.nativeInstance().hash64().hash(),…
When was CVE-2026-59949 disclosed?
CVE-2026-59949 was first published on July 24, 2026, with the most recent update on September 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-59949 actively exploited?
CVE-2026-59949 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (38th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-59949?
CVE-2026-59949 has a CVSS base score of 6.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-59949?
A fix for CVE-2026-59949 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-59949 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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