go-billy has path traversal vulnerabilities

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.1 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

EPSS

• CVE-2026-44973: 0.31% estimated exploitation activity in the next 30 days; percentile 23.97 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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 primitive os.Root. Patches Users should upgrade to a patched version in order to…

Published by the source

14 May 2026, 18:25 UTC

Last modified by the source

9 Jun 2026, 10:26 UTC

Source last checked

26 Oct 2026, 15:23 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-qw64-3x98-g7q2

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# Patch Next advisory brief: CVE-2026-44973

Advisory: go-billy has path traversal vulnerabilities
IDs: CVE-2026-44973, GHSA-qw64-3x98-g7q2
Record: https://patchnext.com/advisories/cve-2026-44973 (revision 1, source checked 26 Oct 2026, 15:23 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/go-git/go-billy/v6 6.0.0-alpha.1; github.com/go-git/go-billy/v5 5.9.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/go-git/go-billy/v6: affected < 6.0.0-alpha.1; fixed in 6.0.0-alpha.1
- Go github.com/go-git/go-billy/v5: affected < 5.9.0; fixed in 5.9.0

## Suggested inspection (read-only)
- Go github.com/go-git/go-billy/v6: check the installed version with your package manager.
- Go github.com/go-git/go-billy/v5: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/go-git/go-billy/v6, github.com/go-git/go-billy/v5.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-qw64-3x98-g7q2 (GitHub-reviewed advisory GHSA-qw64-3x98-g7q2 lists affected ranges: Go github.com/go-git/go-billy/v5 >=0 =0 <6.0.0-alpha.1)

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