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Fencer Vulns
medium 6.5

CVE-2019-15903 json

In libexpat before 2.2.8, crafted XML input could fool the parser into changing from DTD parsing to...

published 2019-09-04 7 y ago modified 2026-10-14 26 d ago also EUVD-2019-6813 , JLSEC-2025-41

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
6.6%
EPSS 6.6% chance of exploitation in 30 days, percentile 93%
public exploits
0
none known

Summary

In libexpat before 2.2.8, crafted XML input could fool the parser into changing from DTD parsing to document parsing too early; a consecutive call to XML_GetCurrentLineNumber (or XML_GetCurrentColumnNumber) then resulted in a heap-based buffer over-read.

Patch / fix

  • julia Expat_jll 2.2.10+0
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP V3.1.5
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • expat Debian 14, Debian 13, Debian 12 2.2.7-2
  • firefox-esr Debian 14, Debian 13, Debian 12 68.2.0esr-1
  • thunderbird Debian 14, Debian 13, Debian 12 1:68.2.1-1

debian advisories DEBIAN-CVE-2019-15903

  • expat Ubuntu 16.04 LTS 2.1.0-7ubuntu0.16.04.5
  • expat Ubuntu 18.04 LTS 2.2.5-3ubuntu0.2
  • firefox Ubuntu 16.04 LTS 70.0+build2-0ubuntu0.16.04.1
  • firefox Ubuntu 18.04 LTS 70.0+build2-0ubuntu0.18.04.1
  • firefox Ubuntu 20.04 LTS 70.0+build2-0ubuntu1
  • thunderbird Ubuntu 16.04 LTS 1:68.7.0+build1-0ubuntu0.16.04.2
  • thunderbird Ubuntu 18.04 LTS 1:68.2.1+build1-0ubuntu0.18.04.1
  • chromium-browser Ubuntu 16.04 LTS 78.0.3904.70-0ubuntu0.16.04.2

ubuntu advisories UBUNTU-CVE-2019-15903

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • thunderbird RHEL 6 68.2.0-2.el6_10
  • thunderbird RHEL 7 68.2.0-1.el7_7
  • thunderbird RHEL 8 68.2.0-1.el8_0
  • firefox RHEL 7 68.2.0-1.el7_7
  • firefox RHEL 8 68.2.0-2.el8_0
  • jbcs-httpd24-curl jboss core services 1 7.64.1-36.jbcs.el6
  • jbcs-httpd24-curl jboss core services 1 7.64.1-36.jbcs.el7
  • jbcs-httpd24-httpd jboss core services 1 2.4.37-57.jbcs.el6

red hat advisories RHSA-2025:22871RHSA-2019:3756RHSA-2019:3210RHSA-2019:3237RHSA-2019:3193RHSA-2019:3196

  • expat Linux Micro 6.1 2.7.1-slfo.1.1_1.1
  • expat Linux Micro 6.0 2.7.1-1.1
  • python36 SLES for SAP 12 SP5, SLES 12 SP5 3.6.10-4.3.5
  • python36-base SLES for SAP 12 SP5, SLES 12 SP5 3.6.10-4.3.5
  • python3 SLE Module for Basesystem 15 SP1, SLE Module for Basesystem 15 3.6.10-3.42.2
  • python3-base SLE Module for Development Tools 15 SP1, SLE Module for Development Tools 15, SLE Module for Basesystem 15 SP1 +1 more 3.6.10-3.42.2
  • MozillaThunderbird SLE Workstation Extension 15 SP1, SLE Workstation Extension 15 68.2.1-3.58.1
  • MozillaFirefox SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +17 more 68.2.0-109.95.2

suse advisories SUSE-SU-2025:20311-1SUSE-SU-2025:20207-1SUSE-SU-2020:0302-1SUSE-SU-2019:14246-1SUSE-SU-2020:0114-1SUSE-SU-2019:2912-1

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 92.0-1.2
  • MozillaThunderbird openSUSE Tumbleweed 91.1.1-1.1
  • chromium openSUSE Tumbleweed 93.0.4577.82-1.1
  • expat openSUSE Tumbleweed 2.4.1-1.2
  • python36 openSUSE Tumbleweed 3.6.15-1.1
  • chromium openSUSE Tumbleweed 113.0.5672.92-1.1
  • python3 openSUSE Leap 15.1 3.6.10-lp151.6.7.1

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10600-1openSUSE-SU-2024:10601-1openSUSE-SU-2024:10681-1openSUSE-SU-2024:10748-1openSUSE-SU-2024:11284-1

  • expat Rocky Linux 8 2.2.5-4.el8

rocky linux advisories RLSA-2020:4484

  • expat Alpine 3.24, Alpine 3.23, Alpine 3.22 +15 more 2.2.7-r1
  • firefox Alpine 3.23, Alpine 3.22, Alpine 3.21 +9 more 70.0-r0
  • python2 Alpine 3.15, Alpine 3.14, Alpine 3.13 +4 more 2.7.17-r0
  • librewolf Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 70.0-r0
  • firefox-esr Alpine 3.23, Alpine 3.22, Alpine 3.21 +10 more 68.2.0-r0
  • python2-tkinter Alpine 3.11, Alpine 3.10 2.7.17-r0

alpine advisories ALPINE-CVE-2019-15903

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • chromium Arch Linux 78.0.3904.70-1
  • thunderbird Arch Linux 68.2.0-1
  • firefox Arch Linux 70.0-1

arch linux advisories AVG-1053AVG-1054AVG-1055

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-2019-15903 updated cvss 7.5

expat: heap-based buffer over-read via crafted XML input

  • Red Hat Enterprise Linux 5 expat, firefox, xmlrpc-c, thunderbird Red Hat Enterprise Linux 6 expat, firefox, compat-expat1
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 mingw-expat, mingw32-expat, mingw64-expat
    affected: workaround, no fix available
  • Red Hat JBoss Enterprise Application Platform 6 httpd, mod_ssl, mod_ldap, httpd-tools, httpd-manual Red Hat JBoss Enterprise Web Server 2 jbcs-httpd24, jbcs-httpd24-runtime
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat OpenShift Do 1 openshiftdo/odo-init-image-rhel7 1.1.3-2
    fixed: vendor fix RHSA-2021:0949
  • Red Hat Enterprise Linux AppStream (v. 8) firefox 68.2.0-2.el8_0, thunderbird 68.2.0-1.el8_0
    fixed: vendor fix RHSA-2019:3196
  • Red Hat Enterprise Linux BaseOS (v. 8) expat 2.2.5-4.el8
    fixed: vendor fix RHSA-2020:4484
  • Red Hat Enterprise Linux BaseOS AUS (v. 8.2) expat 2.2.10-1.el8_2
    fixed: vendor fix RHSA-2025:22871
  • Red Hat Enterprise Linux Client (v. 7) expat 2.1.0-12.el7, firefox 68.2.0-1.el7_7, thunderbird 68.2.0-1.el7_7 Red Hat Enterprise Linux Client Optional (v. 7) firefox 68.2.0-1.el7_7
    fixed: vendor fix RHSA-2019:3193
show 10 more
  • Red Hat Enterprise Linux ComputeNode (v. 7) expat 2.1.0-12.el7 Red Hat Enterprise Linux ComputeNode Optional (v. 7) expat-devel 2.1.0-12.el7, expat-static 2.1.0-12.el7, expat-debuginfo 2.1.0-12.el7
    fixed: vendor fix RHSA-2020:3952
  • Red Hat Enterprise Linux Desktop (v. 6) thunderbird 68.2.0-2.el6_10
    fixed: vendor fix RHSA-2019:3756
  • Red Hat Enterprise Linux Server (v. 7) expat 2.1.0-12.el7, firefox 68.2.0-1.el7_7
    fixed: vendor fix RHSA-2019:3193
  • Red Hat Enterprise Linux Server Optional (v. 6) thunderbird 68.2.0-2.el6_10
    fixed: vendor fix RHSA-2019:3756
  • Red Hat Enterprise Linux Server Optional (v. 7) firefox 68.2.0-1.el7_7, thunderbird 68.2.0-1.el7_7
    fixed: vendor fix RHSA-2019:3193
  • Red Hat Enterprise Linux Workstation (v. 6) thunderbird 68.2.0-2.el6_10
    fixed: vendor fix RHSA-2019:3756
  • Red Hat Enterprise Linux Workstation (v. 7) expat 2.1.0-12.el7, firefox 68.2.0-1.el7_7, thunderbird 68.2.0-1.el7_7 Red Hat Enterprise Linux Workstation Optional (v. 7) firefox 68.2.0-1.el7_7
    fixed: vendor fix RHSA-2019:3193
  • Red Hat JBoss Core Services
    fixed: vendor fix RHSA-2020:2646
  • Red Hat JBoss Core Services on RHEL 6 Server jbcs-httpd24-curl 7.64.1-36.jbcs.el6, jbcs-httpd24-httpd 2.4.37-57.jbcs.el6, jbcs-httpd24-mod_md 2.0.8-24.jbcs.el6, jbcs-httpd24-libcurl 7.64.1-36.jbcs.el6, jbcs-httpd24-mod_ssl 2.4.37-57.jbcs.el6, jbcs-httpd24-nghttp2 1.39.2-25.jbcs.el6, +12 more Red Hat JBoss Core Services on RHEL 7 Server jbcs-httpd24-curl 7.64.1-36.jbcs.el7, jbcs-httpd24-httpd 2.4.37-57.jbcs.el7, jbcs-httpd24-mod_md 2.0.8-24.jbcs.el7, jbcs-httpd24-libcurl 7.64.1-36.jbcs.el7, jbcs-httpd24-mod_ssl 2.4.37-57.jbcs.el7, jbcs-httpd24-nghttp2 1.39.2-25.jbcs.el7, +13 more
    fixed: vendor fix RHSA-2020:2644
  • Red Hat Enterprise Linux 5 xulrunner Red Hat Enterprise Linux 6 xulrunner Red Hat Enterprise Linux 7 python, tkinter, xulrunner, python-libs, python-test, python-tools Red Hat Enterprise Linux 8 python2, python3, python2-libs, python2-test, python3-idle, python3-libs, +5 more Red Hat Enterprise Linux BaseOS AUS (v. 8.2) expat 2.2.10-1.el8_2
    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 ICSA-23-348-10 updated cvss 7.5

Siemens SIMATIC S7-1500

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.0, < 3.1.5
    affected: fixed in V3.1.5, mitigation support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
17 mo ago

Exploit prediction

6.64% chance of exploitation in the next 30 days, higher than 93% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/libexpat/libexpat/issues/317 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
julia Expat_jll
<2.2.10+0
2.2.10+0

Affected products

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Classification

Weakness
  • CWE-125 Out-of-bounds Read
  • CWE-776 Improper Restriction of Recursive Entity References in DTDs

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.