# CVE-2026-88078: Microsoft Edge cryptographic signature verification bypass

Source: https://junglewise.ai/threats/cve-2026-88078-improper-verification-of-cryptographic-signature-in-microsoft  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-29. Updated: 2026-10-29  
License: CC BY 4.0 with a link back

CVE-2026-88078 · Severity: medium · CVSS 4.3 · Published 2026-10-29

Microsoft Edge, a web browser used by millions of users worldwide, does not properly verify cryptographic signatures, allowing an attacker to impersonate legitimate websites or services. An attacker on the network could trick users into trusting malicious content that appears to come from legitimate sources, potentially leading to credential theft, malware distribution, or other social engineering attacks.

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

## Quick answers

**Is CVE-2026-88078 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-88078 being exploited in the wild.

**How severe is CVE-2026-88078?** Medium severity, with a CVSS score of 4.3, published 29 October 2026.

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

**Is there a fix for CVE-2026-88078?** 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-2026-88078 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-88078?** Check whether you run Microsoft Edge 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

The vulnerability is an improper verification of cryptographic signatures in Microsoft Edge (Chromium-based browser). The attack vector is network-based and requires no authentication; an attacker positioned on the network can exploit this to perform spoofing attacks against users of the browser. A patch exists to address this issue.

## Affected products

- Microsoft Edge <UNKNOWN>

## Timeline

- 2026-10-29: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88078](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88078)

## Related threats

- [Microsoft Edge out-of-bounds read information disclosure](https://junglewise.ai/threats/cve-2026-122518-out-of-bounds-read-in-microsoft-edge-chromium-based-allows-an)
- [Microsoft Edge privilege escalation via incorrect authorization](https://junglewise.ai/threats/cve-2026-69446-incorrect-authorization-in-microsoft-edge-chromium-based-allows)
- [Microsoft Edge use-after-free privilege elevation](https://junglewise.ai/threats/cve-2026-96203-use-after-free-in-microsoft-edge-chromium-based-allows-an)
- [Microsoft Edge heap-based buffer overflow](https://junglewise.ai/threats/cve-2026-96199-heap-based-buffer-overflow-in-microsoft-edge-chromium-based)
- [Microsoft Edge heap-based buffer overflow](https://junglewise.ai/threats/cve-2026-96198-heap-based-buffer-overflow-in-microsoft-edge-chromium-based)