Quick answers
- Is CVE-2026-77504 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-77504 being exploited in the wild.
- How severe is CVE-2026-77504?
- High severity, with a CVSS score of 8.8, published 8 September 2026.
- Which products and versions are affected?
- Microsoft Office Word.
- Is there a fix for CVE-2026-77504?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-77504 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-77504?
- Check whether you run Microsoft Office Word. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A double free vulnerability exists in Microsoft Office Word's memory management, where the same memory region is freed twice during document parsing. The vulnerability is triggered when processing a specially crafted Word document, requiring no authentication and exploitable remotely through document sharing or embedding. An attacker can achieve arbitrary code execution with the privileges of the user running Word. The vulnerability carries a CVSS score of 8.8, indicating high severity with network-based attack capability.
Affected products
- Microsoft Office Word
Timeline
- 2026-09-08: disclosed