CVE-2026-6210: Type confusion and heap-buffer-overflow in Qt SVG marker handling causing application crash
A type confusion vulnerability in Qt SVG allows an attacker to cause an application crash via a crafted SVG image.
When processing SVG marker references, the renderer retrieves a node by its id attribute and casts it to QSvgMarker without verifying the node type. A non-marker element (such as a <line> element) that references itself as a marker triggers an out-of-bounds heap read due to the object size difference between QSvgLine and QSvgMarker, followed by an endless recursion that bypasses the marker recursion guard through incorrect virtual dispatch. The result is an application crash (denial of service).
This issue affects Qt SVG: from 6.7.0 before 6.8.8, from 6.9.0 before 6.11.1.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Qt SVG (QSvgLine/QSvgMarker)to a version that resolves this vulnerability.Fixed in 6.8.8 - Upgrade
Upgrade
Qt SVG (QSvgLine/QSvgMarker)to a version that resolves this vulnerability.Fixed in 6.11.1 - Upgrade
Upgrade
Qt qtsvgto a version that resolves this vulnerability.Patch 724887
Event History
Frequently Asked Questions
What is the severity of CVE-2026-6210?
CVE-2026-6210 is a high-severity vulnerability that can lead to application crashes due to type confusion and heap-buffer-overflow in Qt SVG.
How do I fix CVE-2026-6210?
To fix CVE-2026-6210, upgrade to versions of Qt SVG above 6.8.8 or above 6.11.1.
What causes CVE-2026-6210?
CVE-2026-6210 is caused by a type confusion vulnerability in the handling of SVG marker references.
What versions of Qt SVG are affected by CVE-2026-6210?
The affected versions of Qt SVG are between 6.7.0 and 6.8.8 and between 6.9.0 and 6.11.1.
Can CVE-2026-6210 be exploited remotely?
Yes, CVE-2026-6210 can potentially be exploited remotely via crafted SVG images.