How severe is GHSA-c55g-rp4x-fx84?

No CVSS score has been assigned to GHSA-c55g-rp4x-fx84 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-c55g-rp4x-fx84?

GHSA-c55g-rp4x-fx84 affects the following packages: directxtk_desktop_win10 (NuGet), directxtk_uwp (NuGet). Ecosystems affected: NuGet.

How do I fix GHSA-c55g-rp4x-fx84?

Update directxtk_desktop_win10 to 2026.5.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-c55g-rp4x-fx84 is resolved across your whole dependency graph.

How do I detect GHSA-c55g-rp4x-fx84 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for directxtk_desktop_win10, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-c55g-rp4x-fx84 if there is no patch (or I can't update yet)?

Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.

Is GHSA-c55g-rp4x-fx84 actively exploited in the wild?

No public exploit code has been indexed for GHSA-c55g-rp4x-fx84 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was GHSA-c55g-rp4x-fx84 published, and has it been updated?

GHSA-c55g-rp4x-fx84 was published on May 18, 2026 and was last updated on May 18, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

.NET NuGet

Not in CISA KEV

GHSA-c55g-rp4x-fx84 — directxtk_desktop_win10

Fix: microsoft/DirectXTK@ef1bd5d

GHSA-c55g-rp4x-fx84 is a remote code execution vulnerability in directxtk_desktop_win10. A fix is available for directxtk_desktop_win10 — see the affected versions and patch details below.

Microsoft DirectX: .spritefont multiply overflow only in 32-bit builds

Published

May 18, 2026

Updated

May 18, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of May 18, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

2 pkgs affected

.NETdirectxtk_desktop_win10.NETdirectxtk_uwp

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

Description

Impact

The spritefont reader can be induced to perform a 32-bit overflow multiply that could in theory result in a RCE.

This impacts the use of the DirectX Tool Kit SpriteFont class file loading ctor if given untrusted data files.

Note this only applies to x86/ARM builds of the library. ARM64 and x64 native is not subject to this issue.

Patches

This bug has been fixed in the May 7, 2026 release. Alternatively, users can update their copy of the reader as per this commit.

Workarounds

This does not apply if a project's .spritefont files are all 'trusted' data that were included with an application. It's primarily an issue only if developers are using user-provided or network downloaded spritefont files.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`directxtk_desktop_win10`	all versions	2026.5.8.1`dotnet add package directxtk_desktop_win10 --version 2026.5.8.1`
.NETNuGet	`directxtk_uwp`	all versions	2026.5.8.1`dotnet add package directxtk_uwp --version 2026.5.8.1`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for directxtk_desktop_win10, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update directxtk_desktop_win10 to 2026.5.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-c55g-rp4x-fx84 is resolved across your whole dependency graph.
Workarounds
Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.

Frequently Asked Questions

### Impact The spritefont reader can be induced to perform a 32-bit overflow multiply that could in theory result in a RCE. This impacts the use of the *DirectX Tool Kit* **SpriteFont** class file loading ctor if given untrusted data files. > Note this only applies to x86/ARM builds of the library. ARM64 and x64 native is not subject to this issue. ### Patches This bug has been fixed in the May 7, 2026 release. Alternatively, users can update their copy of the reader as per [this commit](https://github.com/microsoft/DirectXTK/commit/ef1bd5d7f492c39dd0cd87493ba8ea38725c9791). ### Workaround

O3 Security · Impact-Aware SCA

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