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Fencer Vulns
medium 4.3

CVE-2019-18281 json

An out-of-bounds memory access in the generateDirectionalRuns() function in qtextengine.cpp in Qt qtbase 5.11.x and 5.12.x before 5.12.5 al…

published 2019-10-23 7 y ago modified 2026-06-17 4 mo ago also EUVD-2019-8070

cvss
4.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.8%
EPSS 1.8% chance of exploitation in 30 days, percentile 78%
public exploits
0
none known

Summary

An out-of-bounds memory access in the generateDirectionalRuns() function in qtextengine.cpp in Qt qtbase 5.11.x and 5.12.x before 5.12.5 allows attackers to cause a denial of service by crashing an application via a text file containing many directional characters.

Patch / fix

  • qt qtbase 5.12.5
  • qtbase-opensource-src Debian 14, Debian 13, Debian 12 5.12.5+dfsg-2
  • qtbase-opensource-src-gles Debian 14, Debian 13, Debian 12 5.12.5+dfsg-1

debian advisories DEBIAN-CVE-2019-18281

  • qt5 RHEL 8 5.12.5-3.el8
  • sip RHEL 8 4.19.19-1.el8
  • qt5-qt3d RHEL 8 5.12.5-2.el8
  • qt5-qtdoc RHEL 8 5.12.5-1.el8
  • qt5-qtsvg RHEL 8 5.12.5-1.el8
  • python-qt5 RHEL 8 5.13.1-1.el8
  • qt5-qtbase RHEL 8 5.12.5-4.el8
  • python3-qt5 RHEL 8 5.13.1-1.el8

red hat advisories RHSA-2020:1665

  • qt5 Rocky Linux 8 5.12.5-3.el8
  • qt5-qt3d Rocky Linux 8 5.12.5-2.el8
  • qt5-qtdoc Rocky Linux 8 5.12.5-1.el8
  • qt5-qtsvg Rocky Linux 8 5.12.5-1.el8
  • python-qt5 Rocky Linux 8 5.13.1-1.el8
  • qt5-qtscript Rocky Linux 8 5.12.5-1.el8
  • qt5-qtsensors Rocky Linux 8 5.12.5-1.el8
  • qt5-qtwayland Rocky Linux 8 5.12.5-1.el8

rocky linux advisories RLSA-2020:1665

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-2019-18281 updated cvss 4.3

qt5-qtbase: Out-of-bounds access in generateDirectionalRuns() function in qtextengine.cpp

  • Red Hat CodeReady Linux Builder (v. 8) sip 4.19.19-1.el8 Red Hat Enterprise Linux AppStream (v. 8) qt5 5.12.5-3.el8, sip 4.19.19-1.el8, qt5-qt3d 5.12.5-2.el8, qt5-qtdoc 5.12.5-1.el8, qt5-qtsvg 5.12.5-1.el8, python-qt5 5.13.1-1.el8, +61 more
    fixed: vendor fix RHSA-2020:1665
  • Red Hat Enterprise Linux 7 qt5-qtbase, qt5-qtbase-gui, qt5-rpm-macros, qt5-qtbase-odbc, qt5-qtbase-mysql, qt5-qtbase-common, +2 more
    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

Exploit prediction

1.78% chance of exploitation in the next 30 days, higher than 78% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P

Classification

Weakness
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

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.