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Mallory
Critical

Spoofing / security warning bypass in Microsoft Power Apps external protocol links

IdentifiersCVE-2026-26149CWE-150· Improper Neutralization of Escape,…

CVE-2026-26149 is an improper neutralization of escape, meta, or control sequences vulnerability in Microsoft Power Apps. According to the provided advisory context, the flaw allows an authorized attacker to bypass a security feature over a network. Specifically, successful exploitation can bypass the security warning dialog shown for external protocol links in Power Apps canvas apps. By manipulating how external protocol link content is handled, an attacker can cause users to be misled about the nature of the action being triggered, resulting in spoofing and unintended external protocol invocation on the user’s device. Microsoft assessed the issue as Important, with reporting also describing it as a high-severity Power Apps flaw with a CVSS score of 9.0.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows an attacker to bypass the external protocol security warning dialog in Microsoft Power Apps, enabling spoofing of link behavior and misleading users into launching unintended external protocol handlers on their device. The advisory context further indicates this may enable interaction with other tenants' applications and content. The primary impact is security feature bypass and spoofing, with potential downstream access to external applications or content via user-triggered protocol handling rather than direct code execution.

Mitigation

If you can’t patch tonight, do this now.

Until full remediation is confirmed, avoid interacting with untrusted or suspicious Power Apps canvas apps, especially apps that present or trigger external protocol links. Restrict exposure to untrusted app content, review apps that invoke external protocol handlers, and follow Microsoft's temporary workaround guidance where available. Organizations should monitor Microsoft advisory updates for any revised mitigation or final fix status.

Remediation

Patch, then assume compromise.

Apply Microsoft's available fix for CVE-2026-26149 in Microsoft Power Apps. The provided advisory context states that Microsoft had made a temporary fix/workaround available at the time of publication and that customers should implement the vendor-provided remediation and monitor Microsoft for any final or updated service-side fix guidance. Because Power Apps is a Microsoft-managed platform, remediation may be delivered by the vendor rather than through a traditional customer-installed patch.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
Microsoft CorporationPower Appsapplication
Microsoft CorporationPower Apps Desktop Clientapplication

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What this page doesn’t show

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Exposure mapping

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Threat actor evidence

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Associated malware

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Detection signatures

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Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity1

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