CVE-2026-54616

HIGHPre-NVD 7.17.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 76% of all CVEs by exploit prediction. 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
Elevated
7.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.1Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

NanaZip is the 7-Zip derivative intended for the modern Windows experience. From version 1.0.88.0 until stable version 6.0.1698.0 and preview version 6.5.1742.0, the Lz4Decode function in NanaZip.Core/SevenZip/CPP/7zip/Archive/SquashfsHandler.cpp rejects only a zero return from LZ4_decompress_safe even though malformed input produces a negative error value. The negative int is converted to the unsigned SizeT destLen and then truncated into outBufWasWrittenSize, causing ReadBlock to trust an attacker-inflated _cachedUnpackBlockSize. During fragment extraction, an attacker-controlled inode Offset can make memcpy read beyond the _cachedBlock heap allocation and place adjacent heap contents in the extracted file, or crash the process. This issue is fixed in stable version 6.0.1698.0 and preview version 6.5.1742.0.

CVSS v3
7.1
EG Score
7.1(medium)
EG Risk
48(Track)
EG Risk 48/100SSVC: Track

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
Severity71% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
24%
KEV
Not listed

Published

August 20, 2026

Last Modified

August 20, 2026

Advisory Details (5)

Auto-updated Aug 20, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_release.
github_release Patch Available

NanaZip 6.5 Preview (6.5.1742.0)

Patch available: M2Team/NanaZip 6.5.1742.0 (pre-release)

https://github.com/M2Team/NanaZip/releases/tag/6.5.1742.0
github_release Patch Available

NanaZip 6.0 Update 5 (6.0.1698.0)

Patch available: M2Team/NanaZip 6.0.1698.0

https://github.com/M2Team/NanaZip/releases/tag/6.0.1698.0
github_commit

commit ce0322a1932e (M2Team/NanaZip)

Fix landed in M2Team/NanaZip commit ce0322a1932e — awaiting tagged release

https://github.com/M2Team/NanaZip/commit/ce0322a1932e16a53e4a13e48bc61804c7826956
github_commit

commit 733e8570d2ba (M2Team/NanaZip)

Fix landed in M2Team/NanaZip commit 733e8570d2ba — awaiting tagged release

https://github.com/M2Team/NanaZip/commit/733e8570d2ba96c3e52aab44f5fd886775d5952f
github Patch Available🟡 PoC Available

Heap out-of-bounds read in NanaZip SquashFS LZ4 decompressor via unchecked negative return value (GHSL-2026-124) · Advisory · M2Team/NanaZip · GitHub

https://github.com/M2Team/NanaZip/security/advisories/GHSA-95x5-qvvm-hmfp

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 20× 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. 2026-08-30 05:47 UTCEG score recompute
  2. 2026-08-30 01:22 UTCEPSS rescore
  3. 2026-08-29 06:08 UTCEG score recompute
  4. 2026-08-28 21:41 UTCEPSS rescore
  5. 2026-08-27 18:35 UTCEG score recompute
  6. 2026-08-27 14:25 UTCEPSS rescore
  7. 2026-08-26 18:18 UTCEG score recompute
  8. 2026-08-26 14:46 UTCEPSS rescore
  9. 2026-08-25 18:29 UTCEG score recompute
  10. 2026-08-25 13:49 UTCEPSS rescore
  11. 2026-08-24 18:48 UTCEG score recompute
  12. 2026-08-23 07:22 UTCEG score recompute
  13. 2026-08-23 00:19 UTCEPSS rescore
  14. 2026-08-22 07:46 UTCEG score recompute
  15. 2026-08-21 23:49 UTCEPSS rescore
  16. 2026-08-20 20:20 UTCEG score recompute
  17. 2026-08-20 20:02 UTCEG score recompute
  18. 2026-08-20 17:34 UTCEG score recompute
  19. 2026-08-20 16:17 UTCEG score recompute
  20. 2026-08-20 16:16 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-54616?
CVE-2026-54616 is a high vulnerability published on August 20, 2026. NanaZip is the 7-Zip derivative intended for the modern Windows experience. From version 1.0.88.0 until stable version 6.0.1698.0 and preview version 6.5.1742.0, the Lz4Decode function in NanaZip.Core/SevenZip/CPP/7zip/Archive/SquashfsHandler.cpp rejects only a zero return from LZ4decompresssafe…
When was CVE-2026-54616 disclosed?
CVE-2026-54616 was first published in the National Vulnerability Database on August 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54616 actively exploited?
CVE-2026-54616 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 75.7% of all scored CVEs.
What is the CVSS score of CVE-2026-54616?
CVE-2026-54616 has a CVSS v3 base score of 7.1 (NVD).
How do I remediate CVE-2026-54616?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54616, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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