GHSA-5r97-79vw-qvm4
Microsoft DirectX12: .spritefont multiply overflow only in 32-bit builds
Blast Radius
directxtk12_desktop_win10.NETdirectxtk12_uwpReal-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, you can just update your 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
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | directxtk12_desktop_win10 | all versions | 2026.5.8.1 |
| .NETNuGet | directxtk12_uwp | all versions | 2026.5.8.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for directxtk12_desktop_win10. 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.
Fix
Update directxtk12_desktop_win10 to 2026.5.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5r97-79vw-qvm4 is resolved across your whole dependency graph.
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.
How O3 protects you
O3 pinpoints whether GHSA-5r97-79vw-qvm4 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-5r97-79vw-qvm4. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-5r97-79vw-qvm4 in your dependencies?
O3 detects GHSA-5r97-79vw-qvm4 across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.