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Fencer Vulns
high 8.7

CVE-2026-6210 json

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

published 2026-05-06 6 mo ago modified 2026-07-29 3 mo ago also EUVD-2026-27681

cvss
8.7
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 20%
public exploits
0
none known

Summary

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.

Patch / fix

  • Qt Qt 6.8.8, 6.11.1
  • qt6-svg Debian 14 6.10.2-6

debian advisories DEBIAN-CVE-2026-6210

  • qt6-svg openSUSE Tumbleweed 6.11.0-2.1

opensuse advisories openSUSE-SU-2026:10742-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-6210 updated cvss 6.5

Qt SVG: Qt SVG: Denial of Service via crafted SVG image

  • Red Hat Enterprise Linux 7 qt5-qtsvg, qt5-qtsvg-examples Red Hat Enterprise Linux 8 qt5-qtsvg, qt5-qtsvg-examples Red Hat Enterprise Linux 9 qt5-qtsvg, qt5-qtsvg-examples Red Hat Enterprise Linux 10 qt6-qtsvg
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
6 mo ago

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 8.7 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
CNA 4.0 8.7 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

Affected products

  • Qt Qt

Classification

Weakness
  • CWE-843 Access of Resource Using Incompatible Type
  • CWE-122 Heap-based Buffer Overflow

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.