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Maven
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MEDIUM severity

GHSA-6h7w-fc84-x7p6

MEDIUMFix: http4s/http4s@52e1890

GHSA-6h7w-fc84-x7p6 is a medium-severity (CVSS 5.8) Path Traversal vulnerability in org.http4s:http4s-core. O3 Security confirms whether GHSA-6h7w-fc84-x7p6 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

StaticFile.fromUrl can leak presence of a directory

Also known asCVE-2021-32643
Published
May 28, 2021
Updated
Jul 8, 2026
Affected
4 pkgs
Patched
4 / 4
Exploits
None indexed
Exploitation data as of Jul 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

4 pkgs affected
org.http4s:http4s-coreorg.http4s:http4s-coreorg.http4s:http4s-coreorg.http4s:http4s-core

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Impact

StaticFile.fromUrl can leak the presence of a directory on a server when the URL scheme is not file://, and the URL points to a fetchable resource under its scheme and authority. The function returns F[None], indicating no resource, if url.getFile is a directory, without first checking the scheme or authority of the URL. If a URL connection to the scheme and URL would return a stream, and the path in the URL exists as a directory on the server, the presence of the directory on the server could be inferred from the 404 response. The contents and other metadata about the directory are not exposed.

This affects http4s versions:

  • 0.21.7 through 0.21.23
  • 0.22.0-M1 through 0.22.0-M8
  • 0.23.0-M1
  • 1.0.0-M1 through 1.0.0-M22

Patches

The patch is available in the following versions:

  • v0.21.24
  • v0.22.0-RC1
  • v0.23.0-RC1
  • v1.0.0-M23

Note: a previous version of this advisory incorrectly referred to 0.22.0-M9 and 0.23.0-M2.

Workarounds

Don't call StaticFile.fromUrl with non-file URLs.

For more information

If you have any questions or comments about this advisory:

Affected Packages

4 total 4 fixed
EcosystemPackageVulnerable rangeFix
Mavenorg.http4s:http4s-core0.21.7&&< 0.21.240.21.24
Mavenorg.http4s:http4s-core0.22.0-M1&&< 0.22.0-RC10.22.0-RC1
Mavenorg.http4s:http4s-core0.23.0-M1&&< 0.23.0-RC10.23.0-RC1
Mavenorg.http4s:http4s-core1.0.0-M1&&< 1.0.0-M231.0.0-M23

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.http4s:http4s-core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update org.http4s:http4s-core to 0.21.24 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6h7w-fc84-x7p6 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether GHSA-6h7w-fc84-x7p6 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-6h7w-fc84-x7p6. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact `StaticFile.fromUrl` can leak the presence of a directory on a server when the `URL` scheme is not `file://`, and the URL points to a fetchable resource under its scheme and authority. The function returns `F[None]`, indicating no resource, if `url.getFile` is a directory, without first checking the scheme or authority of the URL. If a URL connection to the scheme and URL would return a stream, and the path in the URL exists as a directory on the server, the presence of the directory on the server could be inferred from the 404 response. The contents and other metadata about the
O3 Security · Impact-Aware SCA

Is GHSA-6h7w-fc84-x7p6 in your dependencies?

O3 detects GHSA-6h7w-fc84-x7p6 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

GHSA-6h7w-fc84-x7p6: StaticFile.fromUrl can… | O3 Security