Quick answers
- Is CVE-2026-78526 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-78526 being exploited in the wild.
- How severe is CVE-2026-78526?
- High severity, with a CVSS score of 8.8, published 8 September 2026.
- Which products and versions are affected?
- Microsoft Office Word <UNKNOWN>.
- Is there a fix for CVE-2026-78526?
- 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-2026-78526 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-78526?
- Check whether you run Microsoft Office Word at an affected version. 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 heap-based buffer overflow exists in Microsoft Office Word's document processing logic. The vulnerability occurs when Word processes a maliciously crafted document, allowing an attacker to write beyond allocated heap memory bounds. An attacker can exploit this remotely by sending a specially crafted Word document (e.g., via email or network share) without requiring user authentication beyond opening the file. Successful exploitation enables remote code execution with the privileges of the user running Word. Patches are expected to be available from Microsoft through their regular security update cycle.
Affected products
- Microsoft Office Word <UNKNOWN>
Timeline
- 2026-09-08: disclosed