CVE-2026-19395
Description
A flaw was found in Qt for MCUs. When processing styled text in a Text element, the text parser improperly handles an image () tag containing an attribute with an empty value. An attacker can exploit this issue by supplying specially crafted styled text, causing an internal validation check to fail and triggering the error handler to halt the device, resulting in a Denial of Service (DoS).
Statement
Red Hat Product Security has rated this vulnerability as having an Important severity because an unauthenticated remote attacker could trigger a complete denial of service leading to a device halt when processing untrusted markup. This flaw is specific to the Qt for MCUs framework designed for microcontroller targets. Standard Qt packages distributed across Red Hat products do not include this microcontroller-specific codebase and are not affected.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
While assertion is good for catching logic errors and reducing the chances of reaching more serious vulnerability conditions, an attacker can still cause a denial of service if they can trigger an assert statement, and if the scope of the assert() extends beyond the attacker's own session. For example, if a server handles multiple simultaneous connections, if an assert() occurs in one single connection that causes all other connections to be dropped, this could be a significant denial of service.
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