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

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-6210
StatePUBLISHED
AssignerTQtC
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-05-06 12:16:49 UTC
Updated2026-05-07 15:10:53 UTC
DescriptionA 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.

Risk And Classification

Primary CVSS: v4.0 8.7 HIGH from a59d8014-47c4-4630-ab43-e1b13cbe58e3

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.000550000 probability, percentile 0.171880000 (date 2026-05-12)

Problem Types: CWE-122 | CWE-843 | CWE-843 CWE-843 Access of Resource Using Incompatible Type ('Type Confusion') | CWE-122 CWE-122 Heap-based Buffer Overflow

VersionSourceTypeScoreSeverityVector
4.0a59d8014-47c4-4630-ab43-e1b13cbe58e3Secondary8.7HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS8.7HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
None
Availability
High
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA The Qt Company Qt affected 6.7.0 6.8.8 python Not specified
CNA The Qt Company Qt affected 6.9.0 6.11.1 python Not specified

References

ReferenceSourceLinkTags
issues.oss-fuzz.com/issues/496327371 a59d8014-47c4-4630-ab43-e1b13cbe58e3 issues.oss-fuzz.com
codereview.qt-project.org/c/qt/qtsvg/+/724887 a59d8014-47c4-4630-ab43-e1b13cbe58e3 codereview.qt-project.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Additional Advisory Data

Solutions

CNA: Apply fix: https://codereview.qt-project.org/c/qt/qtsvg/+/724887

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report