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
This low-severity CVE scores 2.4 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).
- Lower severity and no public exploit yet
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(medium)
- EG Risk
- 27(Track)EG Risk 27/100SSVC: 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 computedSeverity24% × 45%Exploitation40% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 35%
- KEV
- Not listed
Published
July 10, 2026
Last Modified
July 13, 2026
References (4)
- 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
- 134c704f-9b21-4f2e-91b3-4a467353bcc0https://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 8× in last 7d / 35× 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.
- 2026-08-26 14:46 UTCEPSS rescore
- 2026-08-25 13:49 UTCEPSS rescore
- 2026-08-24 09:44 UTCEG score recompute
- 2026-08-23 00:19 UTCEPSS rescore
- 2026-08-21 23:49 UTCEPSS rescore
- 2026-08-21 04:40 UTCEG score recompute
- 2026-08-20 22:55 UTCEPSS rescore
- 2026-08-19 17:04 UTCEPSS rescore
- 2026-08-18 13:48 UTCEPSS rescore
- 2026-08-17 23:35 UTCEG score recompute
- 2026-08-17 13:47 UTCEPSS rescore
- 2026-08-16 14:56 UTCEPSS rescore
- 2026-08-16 02:14 UTCEPSS rescore
- 2026-08-15 01:30 UTCEPSS rescore
- 2026-08-14 18:32 UTCEG score recompute
- 2026-08-13 22:00 UTCEPSS rescore
- 2026-08-12 13:51 UTCEPSS rescore
- 2026-08-11 13:28 UTCEG score recompute
- 2026-08-11 00:00 UTCEPSS rescore
- 2026-08-09 13:46 UTCEPSS rescore
- 2026-08-08 16:37 UTCEPSS rescore
- 2026-08-08 08:25 UTCEG score recompute
- 2026-08-06 13:47 UTCEPSS rescore
- 2026-08-05 19:17 UTCEPSS rescore
- 2026-08-05 03:22 UTCEG score recompute
Show 29 moreShow fewer
- 2026-08-04 15:10 UTCEPSS rescore
- 2026-08-04 10:39 UTCEPSS rescore
- 2026-08-03 10:36 UTCEPSS rescore
- 2026-08-02 02:27 UTCEPSS rescore
- 2026-08-01 22:18 UTCEG score recompute
- 2026-08-01 04:16 UTCEPSS rescore
- 2026-07-30 16:28 UTCEPSS rescore
- 2026-07-30 01:30 UTCEPSS rescore
- 2026-07-29 17:15 UTCEG score recompute
- 2026-07-28 15:37 UTCEPSS rescore
- 2026-07-26 12:10 UTCEG score recompute
- 2026-07-25 14:18 UTCEPSS rescore
- 2026-07-24 14:18 UTCEPSS rescore
- 2026-07-23 03:20 UTCEG score recompute
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:25 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-18 10:04 UTCEPSS rescore
- 2026-07-16 17:03 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-13 22:31 UTCEPSS rescore
- 2026-07-13 06:13 UTCEPSS rescore
- 2026-07-13 06:13 UTCEPSS rescore
- 2026-07-12 05:46 UTCEPSS rescore
- 2026-07-10 17:13 UTCEG score recompute
- 2026-07-10 17:12 UTCMITRE cvelistV5first tracked
Publicly available exploits
(1 reference)Working exploit code is in the public domain (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.
- Exploit-DBEDB-52652First seen Aug 17, 2026
NanaZip 6.5 - DoS
Open source ↗
Related CVEs(same CWE)
Same CWE
10 shownCWE-400
Frequently asked(5)
What is CVE-2026-55780?
When was CVE-2026-55780 disclosed?
Is CVE-2026-55780 actively exploited?
What is the CVSS score of CVE-2026-55780?
How do I remediate CVE-2026-55780?
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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