NanaZip is the 7-Zip derivative intended for the modern Windows experience. Prior to 6.5.1749.0, NanaZip's .NET single-file bundle handler in NanaZip.Codecs.Archive.DotNetSingleFile.cpp sizes its extraction buffer from the bundle entry Size field, which is only checked for sign and is not validated against the real file size. A crafted bundle can cause an attacker-chosen allocation inside Extract, where std::bad_alloc or std::length_error can escape across the COM STDMETHODCALLTYPE boundary and crash the process. This issue is fixed in version 6.5.1749.0.
CVE-2026-55780
LOWPre-NVD 2.42.4
EchelonGraph scoreLOW confidence
This low-severity CVE scores 2.4 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). 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: cna:github_m
2.4
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: —CVSS: 2.4Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 2.4
- EG Score
- 2.4(low)
- EPSS
- —
- KEV
- Not listed
Published
July 10, 2026
Last Modified
July 10, 2026
References (3)
- security-advisories@githubhttps://github.com/M2Team/NanaZip/commit/ad62e3b4970b9f01e924c99094d6fed7a42f849a
- security-advisories@githubhttps://github.com/M2Team/NanaZip/releases/tag/6.5.1749.0
- security-advisories@githubhttps://github.com/M2Team/NanaZip/security/advisories/GHSA-ppm9-5267-rq72
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 2× in last 7d / 2× 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.
- 2026-07-10 17:13 UTCEG score recompute
- 2026-07-10 17:12 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Same CWE
10 shownCWE-400 · CWE-248
Frequently asked(4)
What is CVE-2026-55780?
CVE-2026-55780 is a low vulnerability published on July 10, 2026. NanaZip is the 7-Zip derivative intended for the modern Windows experience. Prior to 6.5.1749.0, NanaZip's .NET single-file bundle handler in NanaZip.Codecs.Archive.DotNetSingleFile.cpp sizes its extraction buffer from the bundle entry Size field, which is only checked for sign and is not validated…
When was CVE-2026-55780 disclosed?
CVE-2026-55780 was first published in the National Vulnerability Database on July 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-55780?
CVE-2026-55780 has a CVSS v3 base score of 2.4 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-55780?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55780, 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
Explore the affected products and dependency analysis for CVE-2026-55780
Is Your Infrastructure Affected by CVE-2026-55780?
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