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Fencer Vulns
low 2.3

CVE-2026-78253 json

Denial-of-service (stack-exhaustion) vulnerability in QXmlStreamReader::readElementText() impacts Qt

published 2026-09-23 46 d ago modified 2026-09-24 45 d ago also EUVD-2026-85238

cvss
2.3
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 37%
public exploits
0
none known

Summary

Uncontrolled recursion in QXmlStreamReader::readElementText() in Qt Group Qt allows attackers to cause a denial of service (application crash via stack exhaustion) via a crafted XML document.

Patch / fix

  • qt6-base Debian 14 6.11.2+dfsg-5
  • qtbase-opensource-src Debian 14 5.15.19+dfsg-6

debian advisories DEBIAN-CVE-2026-78253

  • qt6-qtbase hummingbird 1 6.11.2-2.hum1
  • qt6-qtbase-gui hummingbird 1 6.11.2-2.hum1
  • qt6-qtbase-odbc hummingbird 1 6.11.2-2.hum1
  • qt6-qtbase-ibase hummingbird 1 6.11.2-2.hum1
  • qt6-qtbase-mysql hummingbird 1 6.11.2-2.hum1
  • qt6-qtbase-common hummingbird 1 6.11.2-2.hum1
  • qt6-qtbase-examples hummingbird 1 6.11.2-2.hum1
  • qt6-qtbase-postgresql hummingbird 1 6.11.2-2.hum1

red hat advisories RHSA-2026:59393

  • AusweisApp openSUSE Tumbleweed 2.6.0-1.1

opensuse advisories openSUSE-SU-2026:12071-1

  • qtbase Azure Linux 3.0 6.6.3-7

azure linux advisories AZL-106827

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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-2026-78253 updated cvss 4.7

qt: Qt: Denial of Service via uncontrolled recursion in XML processing

  • Red Hat Enterprise Linux 10 qt6
    affected: no fix available “Fix deferred”
  • Red Hat Hardened Images qt6
    affected: no fix available
  • Red Hat Hardened Images qt6-qtbase 6.11.2-2.hum1, qt6-qtbase-gui 6.11.2-2.hum1, qt6-qtbase-odbc 6.11.2-2.hum1, qt6-qtbase-ibase 6.11.2-2.hum1, qt6-qtbase-mysql 6.11.2-2.hum1, qt6-qtbase-common 6.11.2-2.hum1, +2 more
    fixed: vendor fix RHSA-2026:59393
  • Red Hat Enterprise Linux 6 qt, qt3, qt-x11, qt-odbc, qt-demos, qt-mysql, +10 more Red Hat Enterprise Linux 7 qt, qt3, qt-x11, qt-odbc, qt-qvfb, qt-demos, +12 more Red Hat Enterprise Linux 8 qt5, qt5-rpm-macros, qt5-srpm-macros Red Hat Enterprise Linux 9 qt5, qt5-rpm-macros, qt5-srpm-macros Red Hat Hardened Images qt5
    not affected: vulnerable code not present

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
no
Technical impact
partial
Assessed
46 d ago

Exploit prediction

0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 2.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/S:N/AU:N/R:U/RE:L/U:Green
CNA 4.0 2.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/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:N/AU:N/R:U/V:X/RE:L/U:Green

Affected products

  • qt qt

Classification

Weakness

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.