CVE-2026-78502 Microsoft CVE debrief

Who should care

Defenders responsible for Microsoft Office Word installations, particularly in environments where information disclosure could have significant consequences

Why it matters

CVE-2026-78502 is a Medium-severity vulnerability in Microsoft Office Word that allows unauthorized information disclosure over a network. Defenders should assess exposure, prioritize patching, and monitor for potential disclosure attempts.

• Potential information disclosure over the network
• Need to verify exposure of Microsoft Office Word installations
• Priority to apply patches from Microsoft
• Monitoring for potential information disclosure attempts

Technical summary

CVE-2026-78502 is an out-of-bounds read vulnerability in Microsoft Office Word that allows an unauthorized attacker to disclose information over a network. The vulnerability has a CVSS score of 6.5 and is considered Medium severity. It affects Microsoft Office Word installations, and defenders should assess exposure and apply patches from Microsoft as available. The CVE record and NVD entry provide details on the vulnerability.

Defensive priority

Medium priority for defenders to assess exposure and apply patches

Recommended defensive actions

• Assess exposure of Microsoft Office Word installations to this vulnerability
• Apply patches from Microsoft as available
• Monitor for potential information disclosure attempts

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, but specific version information and exploitation details are not provided. The vulnerability has a CVSS score of 6.5 and is considered Medium severity. There is no information on known or unknown affected scope. Defenders should verify exposure of Microsoft Office Word installations and apply patches from Microsoft as available.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.