rikyoz bit7z up to 4.0.11 restoreSymlink path traversal

Summaryinfo

A vulnerability labeled as critical has been found in rikyoz bit7z up to 4.0.11. This impacts the function SafeOutPathBuilder::restoreSymlink. Executing a manipulation can lead to path traversal. The identification of this vulnerability is CVE-2026-45380. The attack can only be executed locally. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as problematic was found in rikyoz bit7z up to 4.0.11. This vulnerability affects the function SafeOutPathBuilder::restoreSymlink. The manipulation with an unknown input leads to a path traversal vulnerability. The CWE definition for the vulnerability is CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. As an impact it is known to affect integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-45380 since 05/12/2026. The exploitation appears to be difficult. The attack needs to be approached locally. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1006.

Upgrading to version 4.0.12 eliminates this vulnerability. The upgrade is hosted for download at github.com.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• rikyoz

Name

• bit7z

Version

• 4.0.0
• 4.0.1
• 4.0.2
• 4.0.3
• 4.0.4
• 4.0.5
• 4.0.6
• 4.0.7
• 4.0.8
• 4.0.9
• 4.0.10
• 4.0.11

Website

• Product: https://github.com/rikyoz/bit7z/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Once again VulDB remains the best source for vulnerability data.

Discussion