CVE-2026-6210

Type confusion and heap-buffer-overflow in Qt SVG marker handling causing application crash

HIGH
8.7
CVSS Score
Published: May 6, 2026 at 11:59 AM UTC
Updated: July 29, 2026 at 10:33 AM UTC
1 product affected across 1 vendorQt

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Severity
HIGH8.7
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.7.0 ≤ v < 6.8.86.9.0 ≤ v < 6.11.16.7.06.9.0
Affected range stops below 6.11.1, so it looks safe — our inference, not a vendor statement
Affected range stops below 6.8.8, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.7HIGHTQtC
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-843CWE-122

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