CVE-2026-44973 Billy: Path traversal vulnerabilities
Attackers can escape intended base directories to access or modify unintended filesystem locations in applications using the go-billy library.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-44973?
CVE-2026-44973 is a high-severity path traversal vulnerability in go-git go-billy, published on 28 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Billy is an interface filesystem abstraction for Go. Prior to 5.9.0, multiple path traversal issues exist across different components of go-billy. Insufficient path sanitization and boundary enforcement may allow crafted paths (e.g., using ..) to escape intended base directories. While go-billy was not originally designed to provide a strong security boundary, some of these issues were inconsistent across some of the built-in implementations. This results in scenarios where applications relying on go-billy for some level of isolation may inadvertently expose access to unintended filesystem locations. This vulnerability is fixed in 5.9.0.
Weakness: CWE-22
Which versions are affected by CVE-2026-44973?
5 open source packages ship an affected version, including github.com/go-git/go-billy/v5 and github.com/go-git/go-billy/v6.
| Package | Affected | Fixed in |
|---|---|---|
github.com/go-git/go-billy/v5 Go | All versions | 5.9.0 |
github.com/go-git/go-billy/v5 Go | All versions | 5.9.0 |
github.com/go-git/go-billy/v5 Go | All versions | 5.9.0 |
github.com/go-git/go-billy/v6 Go | All versions | 6.0.0-alpha.1 |
github.com/go-git/go-billy/v6 Go | All versions | 6.0.0-alpha.1 |
How do I fix CVE-2026-44973?
Upgrade github.com/go-git/go-billy/v5 to 5.9.0 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-44973 being exploited?
There is no known exploitation of CVE-2026-44973 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-44973, CLEANSTART-2026-HQ12968, CLEANSTART-2026-PS39397, CLEANSTART-2026-TX09096, DEBIAN-CVE-2026-44973, GHSA-qw64-3x98-g7q2 and 179 more.