Vulnerability · Published Jun 10, 2026 · Assigned by GitHub_M

CVE-2026-45380bit7z: Path Traversal via Null Byte Injection from `gcount()` Off-by-One in `restoreSymlink()`

Low 3.6

In plain English

A low-severity path traversal in bit7z from rikyoz. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities).

Severity (CVSS 3.1)3.6Low

Exploit odds (30 days)0.1%top 98.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
rikyoz	bit7z	< 4.0.12

Weakness: CWE-22, CWE-193 · Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:L

References

https://github.com/rikyoz/bit7z/security/advisories/GHSA-8wj8-9jwv-j24v x_refsource_CONFIRM
https://github.com/rikyoz/bit7z/releases/tag/v4.0.12 x_refsource_MISC