Quick answers
- Is CVE-2026-66798 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-66798 being exploited in the wild.
- How severe is CVE-2026-66798?
- Medium severity, with a CVSS score of 4.3, published 28 August 2026.
- Which products and versions are affected?
- Microsoft Edge <UNKNOWN>.
- Is there a fix for CVE-2026-66798?
- 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-2026-66798 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-66798?
- Check whether you run Microsoft Edge or Microsoft Edge Chromium 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 use-after-free vulnerability exists in Microsoft Edge (Chromium-based) where freed memory is accessed after deallocation, potentially causing memory corruption. The vulnerability can be exploited over the network by an attacker without authentication by serving a malicious webpage that triggers the vulnerable code path. Successful exploitation allows arbitrary code execution in the browser process with user privileges. Microsoft has released a security update addressing this issue.
Affected products
- Microsoft Edge <UNKNOWN>
Timeline
- 2026-08-28: disclosed