Quick answers
- Is CVE-2026-58403 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-58403 being exploited in the wild.
- How severe is CVE-2026-58403?
- Medium severity, with a CVSS score of 4, published 6 July 2026.
- Which products and versions are affected?
- github.com/gohugoio/hugo (Go) SEMVER:introduced=0.123.0,fixed=0.163.1; Hugo >= 0.123.0, < 0.163.1.
- Is there a fix for CVE-2026-58403?
- Yes. github.com/gohugoio/hugo (Go): upgrade to 0.163.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-58403 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-58403?
- Check whether you run github.com/gohugoio/hugo (Go) or Hugo at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- github.com/gohugoio/hugo (Go): upgrade to 0.163.1 or later
go get github.com/gohugoio/hugo@v0.163.1
Technical details
A regression in Hugo's virtual filesystem (specifically within RootMappingFs.statRoot) caused the application to use Stat instead of Lstat. Because Stat follows symbolic links, an attacker who can place a malicious symlink within a mounted directory (such as a local theme) can bypass the intended filesystem confinement. When Hugo performs a direct file read on such a symlink, it returns the contents of the target file outside the mount tree. This vulnerability affects versions v0.123.0 through v0.163.0 and is fixed in v0.163.1. Exploitation requires the victim to process a malicious local mount or theme; themes downloaded as Go modules are not affected as symlinks are stripped during download.
Affected products
- gohugoio Hugo >= 0.123.0, < 0.163.1
Identifiers
- CVE-2026-58403
- GHSA-c3wq-j5vh-68rc
- GO-2026-5309
Timeline
- 2026-06-10: patched: Fix merged into master branch
- 2026-06-11: advisory: Release v0.163.1 published
- 2026-07-06: disclosed: CVE published to NVD