Patch tracker / KB5120704
KB5120704: Microsoft .NET Framework 4.8 on Window Security Update (August 2026)
KB5120704 is a High security update for Microsoft .NET Framework 4.8 on Window, released 2026-08-11. It closes 3 CVEs with a maximum CVSS of 8.8. The most likely of them to be attacked is CVE-2026-62872, which FIRST.org rates at 6% probability of exploitation in the next 30 days.
Update summary
Fixes 3 CVEs. Most severe CVSS 8.8 (High). EPSS exploit probability up to <1%. Among the lower half of tracked Microsoft updates by EPSS exploit probability.
Microsoft documents 1 known issue with this update.
- Known Issues: After installing the August 2026 .NET Framework cumulative update, some WPF applications may fail with a System.IO.FileFormatException...
Senserva AI Opinion and rich prompt for KB5120704
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5120704
- Released
- 2026-08-11
- Last changed
- 2026-08-12
- Changes tracked
- 2
Senserva began recording day-to-day change history on 2026-07-07, and refreshes it several times a day. Release dates are historical where Microsoft publishes them; revision history is tracked from that date forward, so it does not include changes made before then.
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Known issues, from Microsoft
Quoted from Microsoft's support article for KB5120704 (checked 2026-08-26). Verify against the article before acting.
Known Issues: After installing the August 2026 .NET Framework cumulative update, some WPF applications may fail with a System.IO.FileFormatException when printing or generating PDF/XPS content that uses certain fonts, including Calibri.
Workaround: Applications may mitigate the issue by enabling the Switch.MS.Internal.TtfDelta.DisableCmapAndSbitOverflowProtection AppContext switch in the app config file, as shown below.
<configuration>
<runtime>
<AppContextSwitchOverrides
value="Switch.MS.Internal.TtfDelta.DisableCmapAndSbitOverflowProtection=true"/>
</runtime>
</configuration>
This switch disables security protections introduced in the August 2026 update and may increase exposure to the vulnerabilities addressed by that update. Microsoft recommends using this workaround only as a temporary measure and only when required to address this issue.
Status: Investigating.
CVEs fixed by this update
Sorted exploited-first, then by CVSS. Every CVE links to its Senserva page with the full risk facts, references, and a ready-to-paste AI prompt.
| CVE | Severity | CVSS | EPSS | Exploited |
|---|---|---|---|---|
| CVE-2026-62872 | High | 8.8 | 6.2% | No |
| CVE-2026-65810 | High | 7.8 | 6.2% | No |
| CVE-2026-70354 | High | 7.8 | 6.2% | No |
Scope and sources
- Affected products
- Also released in August 2026
KB5002882
39 CVEs · Critical · exploitedKB5002883
40 CVEs · Critical · exploitedKB5002891
40 CVEs · Critical · exploitedKB5120228
215 CVEs · Critical · exploitedKB5120229
195 CVEs · Critical · exploitedKB5120233
215 CVEs · Critical · exploitedKB5120238
183 CVEs · Critical · exploitedKB5120240
171 CVEs · Critical · exploitedThe full month, summarized: Microsoft Patch Tuesday.
- Authoritative references
See this and every Microsoft update ranked by real-world risk on the Microsoft Patch Tracker.