Vulnerability · Published May 6, 2026 · Assigned by TQtC
CVE-2026-6210Type confusion and heap-buffer-overflow in Qt SVG marker handling causing application crash
High 8.7
In plain English
A high-severity type confusion in Qt from Qt. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:13 | qt6-svg | no fix listed | DEBIAN-CVE-2026-6210 |
| Debian:14 | qt6-svg | 6.10.2-6 | DEBIAN-CVE-2026-6210 |
| Ubuntu:22.04:LTS | qt6-svg | no fix listed | UBUNTU-CVE-2026-6210 |
| Ubuntu:24.04:LTS | qt6-svg | no fix listed | UBUNTU-CVE-2026-6210 |
| Ubuntu:25.10 | qt6-svg | no fix listed | UBUNTU-CVE-2026-6210 |
| Ubuntu:26.04:LTS | qt6-svg | no fix listed | UBUNTU-CVE-2026-6210 |
| Ubuntu:26.10 | qt6-svg | no fix listed | UBUNTU-CVE-2026-6210 |
Affected products (as reported)
Weakness: CWE-843, CWE-122 · Vector: 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