GHSA-2mhw-8qcg-gr96 skia-python vendors vulnerable libfreetype because of pinned cibuildwheel version

Not scored Published 19 Mar 2026

skia-python Linux wheels contain a vulnerable libfreetype due to build environment pinning, allowing potential code execution via crafted fonts.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: Available

What is GHSA-2mhw-8qcg-gr96?

GHSA-2mhw-8qcg-gr96 is a vulnerability in skia-python, published on 19 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

Impact

The Linux wheels for skia-python vendor a vulnerable version of libfreetype that is affected by CVE-2025-27363 [1].

The root cause is a chain of unfortunate events:

skia-python builds wheels using pinned pypa/[email protected] [2]
cibuildwheel 2.21.3 in turn pins manylinux container images [3]
In these images, version 2.9.1-9.el8 of RedHat package freetype is preinstalled. This package version is vulnerable and has since been patched in 2.9.1-10.
During the skia-python Linux build, libfreetype is vendored from the system, resulting in skia-python.libs/libfreetype-29a7443c.so.6.16.1

[ To find the provenance of your vendored libfreetype, we extracted the 8-character hash of the original binary file that is added during the build process (29a7443c), and matched it against our database of hashes all historic Red Hat, Debian and Ubuntu releases of freetype. ]

Because freetype is only a transitive dependency of the packages explicitly installed by the build script [4], it is not upgraded to the patched version [4].
As a result, the published wheels embed a vulnerable libfreetype, even though patched packages are available upstream.

This appears to be a broader manylinux ecosystem issue. The base images do not enforce that yum update runs on container start, so preinstalled libraries may remain vulnerable indefinitely.

Patches

> In the case of skia-python, the solution is to explicitly install freetype in the build process and rebuild the wheels.

The original report was suggesting the above, but in the current build_Linux.sh script, the patched freetype-devel version 2.9.1-10 gets installed as a dependency. It's just that we need to rebuild the wheel for a new release.

Workarounds

Users must upgrade the wheel package after release.

References

Which versions are affected by GHSA-2mhw-8qcg-gr96?

4 open source packages ship an affected version, including skia-python.

Package	Affected	Fixed in
`skia-python` PyPI	All versions	None
`skia-python` PyPI	All versions	None
`skia-python` PyPI	All versions	`144.0.post1`
`skia-python` PyPI	All versions	`144.0.post1`

How do I fix GHSA-2mhw-8qcg-gr96?

Upgrade skia-python to 144.0.post1 or later.

Is GHSA-2mhw-8qcg-gr96 being exploited?

There is no known exploitation of GHSA-2mhw-8qcg-gr96 in the wild and no public exploit code.