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TI-2026-33170 Aliases CVE-2026-45380

bit7z: Path Traversal via Null Byte Injection from `gcount()` Off-by-One in `restoreSymlink()`

Priority MEDIUM 50CWE-193Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Required
Attack complexity
High
Impact type
—
Confidentiality · integrity · availability
None · Low · Low
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

bit7z is a cross-platform C++ static library that allows the compression/extraction of archive files. Prior to version 4.0.12, a one-byte off-by-one error in SafeOutPathBuilder::restoreSymlink() allows an attacker to craft a .7z archive that, when extracted with bit7z on any non-Windows platform, creates a symlink escaping the intended output directory. Subsequent archive entries extracted through this symlink write arbitrary files outside the extraction directory with the permissions of the extracting process. This issue has been patched in version 4.0.12.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00116 1st percentileScored 2026-11-07
Fix Fixed bit7z (rikyoz): 4.0.12

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
rikyozbit7zbefore 4.0.124.0.12Patch availableCNA
  • bit7z Vendorrikyoz Affected before 4.0.12 Fixed in 4.0.12 Patch available CNA

Remediation

  • Fix · CNA bit7z (rikyoz) Fixed in 4.0.12

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-45380

References

Other 2

  • TI-2026-33174 bit7z: Arbitrary File Overwrite via Symlink Attack on Predictable Temp File During Archive Update CVSS 3.1MEDIUM 6.1
  • TI-2026-21569 bit7z has a path traversal vulnerability CVSS 3.1HIGH 7.5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences