PatchTheCVECVE-2026-55783: NanaZip is the 7-Zip derivative intended for the modern Windows experience
CVE-2026-55783 is a low-severity flaw (CVSS 2.4) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
NanaZip is the 7-Zip derivative intended for the modern Windows experience. Prior to 6.5.1749.0, NanaZip's seven in-house IInArchive handlers in NanaZip.Codecs unconditionally dereference the caller-supplied Indices array inside Extract when the archive engine signals extract everything by passing Indices as NULL and NumItems as 0xFFFFFFFF. This causes a NULL pointer dereference in the standard Test archive or Extract all code path for WebAssembl
Why this priority
- No elevated risk signals yet
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 2.4 (Low) |
| Attack vector | Local |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | Passive |
| EPSS exploit chance | 0.2% (top 95%) |
| CISA exploited list | No |
| Weakness | CWE-476 |
| Published | 2026-07-10 |
| Last modified | 2026-10-25 |
Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-55783?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-55783 being exploited?
CVE-2026-55783 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-55783 affect?
CVE-2026-55783 affects affected software. Severity is low (CVSS 2.4). NanaZip is the 7-Zip derivative intended for the modern Windows experience. Prior to 6.5.1749.0, NanaZip's seven in-house IInArchive handlers in NanaZip.Codecs unconditionally dereference the caller-supplied Indices array inside Extract whe
How urgent is CVE-2026-55783?
Priority 10/100. No elevated risk signals yet.
Software pages
Windows vulnerabilities · 7-Zip vulnerabilities