Vulnerability · Published Oct 30, 2026 · Assigned by GitHub_M
CVE-2026-61725sevenz-rust2: unchecked 7z entry paths permit traversal and absolute-path file overwrites
Medium 6.1
In plain English
A medium-severity path traversal in sevenz-rust2 from hasenbanck. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities).
Official description
sevenz-rust2 is a Rust-native 7z compressor and `decompress`or. Prior to 0.21.1, extracting an attacker-supplied 7z archive can write or overwrite files outside the destination directory. In `src/util/decompress.rs`, `decompress_impl` computes each destination with `dest.join(entry.name())` without normalizing the archive's UTF-16 entry name or verifying containment, and `default_entry_extract_fn` writes to it with `File::create`. Parent-directory components escape the extraction root, and an absolute entry path makes the join discard the destination entirely. The convenience entry points `decompress`, `decompress_file`, `decompress_with_password`, and `decompress_file_with_password` all use this default path. Overwriting writable configuration, startup, cron, or build files can lead to code execution or persistence. The archive bytes are the attacker-controlled trust boundary, including for applications that automatically unpack uploaded or otherwise untrusted archives. This issue is fixed in version 0.21.1.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | rust-sevenz-rust2 | no fix listed | DEBIAN-CVE-2026-61725 |
| Ubuntu:26.10 | rust-sevenz-rust2 | no fix listed | UBUNTU-CVE-2026-61725 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| hasenbanck | sevenz-rust2 | < 0.21.1 |
Weakness: CWE-22, CWE-23 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L