# CVE-2026-77490: Microsoft Edge cross-site scripting in page generation

Source: https://junglewise.ai/threats/cve-2026-77490-microsoft-edge-cross-site-scripting-in-page-generation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-11. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-77490 · Severity: medium · CVSS 6.1 · Published 2026-09-11

Microsoft Edge is a web browser used by millions to access the internet and corporate web applications. This vulnerability allows an attacker to inject malicious scripts into web pages, potentially enabling account takeover, credential theft, or malware distribution through spoofed or fraudulent web content. The attack can occur through network-based vectors without requiring special privileges.

Technologies: [Microsoft Edge](https://junglewise.ai/threats/technologies/edge), [Microsoft Edge Chromium](https://junglewise.ai/threats/technologies/edge-chromium). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-77490 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-77490 being exploited in the wild.

**How severe is CVE-2026-77490?** Medium severity, with a CVSS score of 6.1, published 11 September 2026.

**Which products and versions are affected?** Microsoft Edge <UNKNOWN>.

**Is there a fix for CVE-2026-77490?** 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-2026-77490 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-77490?** 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

This is a cross-site scripting (XSS) vulnerability in Microsoft Edge's (Chromium-based) web page generation logic. The root cause is improper neutralization of user-controlled input during HTML rendering, allowing an attacker to inject arbitrary JavaScript code that executes in the browser context. The vulnerability requires network access and likely user interaction (visiting a malicious or compromised website); an attacker can achieve arbitrary script execution in the victim's browser with the same privileges as the user. Patches are expected through Microsoft's standard security update process.

## Affected products

- Microsoft Edge <UNKNOWN>

## Timeline

- 2026-09-11: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-77490](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-77490)

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