go-billy has path traversal vulnerabilities

Open Source Vulnerabilities CVE-2026-44973

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.

Open Source Vulnerabilities GO-2026-5597

Go-billy has path traversal vulnerabilities in github.com/go-git/go-billy

Open Source Vulnerabilities GHSA-qw64-3x98-g7q2

### Impact 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. The `osfs.ChrootOS` implementation is notably affected by this vulnerability and is now deprecated in `v5`, removed at `v6`. Users are recommended to move on to `osfs.BoundOS` instead: `osfs.New(path, WithBoundOS())`. Users requiring stronger security boundary enforcement are recommended to upgrade to `v6`, where the `osfs` implementation are backed by the [traversal-resistant](https://go.dev/blog/osroot) primitive [os.Root](https://pkg.go.dev/os#Root). ### Patches Users should upgrade to a patched version in order to mitigate this vulnerability. Versions prior to `v5` are likely to be affected, users are recommended to upgrade to a supported `go-billy` version. ### Credits Thanks to @faran66 and @vnykmshr for finding and separately reporting this issue privately to the go-git project. 🙇