# CVE-2026-70331: Microsoft Edge for iOS prompt injection vulnerability

Source: https://junglewise.ai/threats/cve-2026-70331-microsoft-edge-for-ios-prompt-injection-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-28. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-70331 · Severity: medium · CVSS 5.4 · Published 2026-08-28

Microsoft Edge for iOS is a web browser used to access online services and content on Apple mobile devices. An attacker can craft malicious web content that exploits how the browser handles LLM prompting, allowing them to perform spoofing attacks—such as impersonating legitimate websites or services—and deceive users into disclosing sensitive information or performing unauthorized actions.

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-2026-70331 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-70331 being exploited in the wild.

**How severe is CVE-2026-70331?** Medium severity, with a CVSS score of 5.4, published 28 August 2026.

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

**Is there a fix for CVE-2026-70331?** 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-2026-70331 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-70331?** Check whether you run Microsoft Edge, Microsoft Edge for iOS 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 vulnerability is an improper neutralization of input used for LLM (Large Language Model) prompting, classified as a prompt injection or similar input-handling flaw. The vulnerability exists in Microsoft Edge for iOS and allows an attacker to inject crafted input that manipulates LLM prompting behavior, enabling spoofing attacks over a network. No specific authentication or elevated privileges are required; an attacker can exploit this via network-accessible content. The attack vector is network-based and does not require user interaction beyond normal browsing. Patches or mitigations should be available through Microsoft's standard security update channels.

## Affected products

- Microsoft Edge for iOS <UNKNOWN>

## Timeline

- 2026-08-28: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70331](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70331)

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