CVE-2022-22826: nextScaffoldPart in xmlparse.c in Expat (aka libexpat) before 2.4.3 has an integer overflow.

Patch / fix

fixed in 4 distros 9 links 2

julia Expat_jll 2.4.4+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

debian ubuntu red hat suse opensuse almalinux rocky linux alpine azure linux

expat Debian 14, Debian 13, Debian 12 2.4.3-1

debian advisories DEBIAN-CVE-2022-22826

expat Ubuntu 18.04 LTS 2.2.5-3ubuntu0.4
expat Ubuntu 20.04 LTS 2.2.9-1ubuntu0.2
expat Ubuntu 22.04 LTS 2.4.3-1
firefox Ubuntu 18.04 LTS 98.0+build3-0ubuntu0.18.04.2
firefox Ubuntu 20.04 LTS 98.0+build3-0ubuntu0.20.04.2
firefox Ubuntu 22.04 LTS 1:1snap1-0ubuntu1
thunderbird Ubuntu 20.04 LTS 1:91.11.0+build2-0ubuntu0.20.04.1
thunderbird Ubuntu 22.04 LTS 1:91.11.0+build2-0ubuntu0.22.04.1

ubuntu advisories UBUNTU-CVE-2022-22826

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

expat RHEL 9 2.2.10-12.el9_0
expat RHEL 7 2.1.0-14.el7_9
expat RHEL 8 2.2.5-4.el8_5.3
xmlrpc-c RHEL 8 1.51.0-8.el8
xmlrpc-c-c++ RHEL 8 1.51.0-8.el8
xmlrpc-c-client RHEL 8 1.51.0-8.el8
xmlrpc-c-client++ RHEL 8 1.51.0-8.el8
expat RHEL 8.2 AUS 2.2.10-1.el8_2

red hat advisories RHSA-2025:22871 RHSA-2025:22785 RHBA-2022:4046 RHSA-2022:1069 RHSA-2022:0951 RHSA-2022:7692

expat SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +11 more 2.1.0-21.12.1
expat SLES for SAP 15 SP2, SLES for SAP 15 SP1, SLES for SAP 15 +19 more 2.2.5-3.9.1
expat SLES 11 SP4-LTSS, SLE Point of Sale 11 SP3 2.0.1-88.42.12.1

suse advisories SUSE-SU-2022:0179-1 SUSE-SU-2022:0178-1 SUSE-SU-2022:14878-1

expat openSUSE Tumbleweed 2.4.3-1.1
expat openSUSE Leap 15.3 2.2.5-3.9.1

opensuse advisories openSUSE-SU-2024:11762-1 openSUSE-SU-2022:0178-1

xmlrpc-c AlmaLinux 8 1.51.0-8.el8
xmlrpc-c-c++ AlmaLinux 8 1.51.0-8.el8
xmlrpc-c-client AlmaLinux 8 1.51.0-8.el8
xmlrpc-c-client++ AlmaLinux 8 1.51.0-8.el8
expat AlmaLinux 8 2.2.5-8.el8_6.2

almalinux advisories ALSA-2022:7692 ALSA-2022:0951

xmlrpc-c Rocky Linux 8 1.51.0-8.el8
expat Rocky Linux 8 2.2.5-4.el8_5.3

rocky linux advisories RLSA-2022:7692 RLSA-2022:0951

expat Alpine 3.12 2.2.10-r0
expat Alpine 3.13 2.2.10-r2
expat Alpine 3.24, Alpine 3.23, Alpine 3.22 +8 more 2.4.3-r0

alpine advisories ALPINE-CVE-2022-22826

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

expat CBL-Mariner 2.0 2.4.3-1

azure linux advisories AZL-7160

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

github.com/libexpat/libexpat#539 pull request
cert-portal.siemens.com/productcert/pdf/ssa-484086.pdf advisory

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-2022-22826 updated 2026-11-07 cvss 8.8

expat: Integer overflow in nextScaffoldPart in xmlparse.c

Red Hat Enterprise Linux 6 expat, firefox, xulrunner, thunderbird
affected: no fix planned “Out of support scope”
Red Hat Enterprise Linux 7 firefox, xulrunner, thunderbird
affected: no fix available, no fix planned “Will not fix”
Red Hat Enterprise Linux 8 firefox, thunderbird
affected: no fix available
Red Hat CodeReady Linux Builder (v. 8) xmlrpc-c-c++ 1.51.0-8.el8, xmlrpc-c-client++ 1.51.0-8.el8
fixed: vendor fix RHSA-2022:7692
Red Hat Enterprise Linux AppStream (v. 9) expat-devel 2.2.10-12.el9_0, expat-debuginfo 2.2.10-12.el9_0, expat-debugsource 2.2.10-12.el9_0
fixed: vendor fix RHBA-2022:4046
Red Hat Enterprise Linux BaseOS (v. 8) expat 2.2.5-4.el8_5.3, xmlrpc-c 1.51.0-8.el8, xmlrpc-c-client 1.51.0-8.el8
fixed: vendor fix RHSA-2022:0951
Red Hat Enterprise Linux BaseOS (v. 9) expat 2.2.10-12.el9_0
fixed: vendor fix RHBA-2022:4046
Red Hat Enterprise Linux BaseOS AUS (v. 8.2) expat 2.2.10-1.el8_2
fixed: vendor fix RHSA-2025:22871

show 4 more

Red Hat Enterprise Linux BaseOS AUS (v.8.4) expat 2.2.10-1.el8_4 Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) expat 2.2.10-1.el8_4
fixed: vendor fix RHSA-2025:22785
Red Hat Enterprise Linux Client (v. 7) expat 2.1.0-14.el7_9 Red Hat Enterprise Linux Client Optional (v. 7) expat-devel 2.1.0-14.el7_9, expat-static 2.1.0-14.el7_9, expat-debuginfo 2.1.0-14.el7_9 Red Hat Enterprise Linux ComputeNode Optional (v. 7) expat-devel 2.1.0-14.el7_9, expat-static 2.1.0-14.el7_9, expat-debuginfo 2.1.0-14.el7_9 Red Hat Enterprise Linux Server (v. 7) expat 2.1.0-14.el7_9 Red Hat Enterprise Linux Server Optional (v. 7) expat-static 2.1.0-14.el7_9, expat-debuginfo 2.1.0-14.el7_9 Red Hat Enterprise Linux Workstation (v. 7) expat 2.1.0-14.el7_9

+1 more productsfewer

Red Hat Enterprise Linux Workstation Optional (v. 7) expat-static 2.1.0-14.el7_9, expat-debuginfo 2.1.0-14.el7_9

fixed: vendor fix RHSA-2022:1069
Red Hat JBoss Core Services
fixed: vendor fix RHSA-2022:7144
Red Hat Enterprise Linux 9 firefox, xmlrpc-c, firefox-x11, thunderbird, xmlrpc-c-c++, xmlrpc-c-client, +1 more Red Hat Enterprise Linux BaseOS AUS (v. 8.2) expat 2.2.10-1.el8_2 Red Hat Enterprise Linux BaseOS AUS (v.8.4) expat 2.2.10-1.el8_4 Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) expat 2.2.10-1.el8_4
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 2025-08-12 cvss 8.8

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 ICSA-22-167-17 updated 2024-07-09 cvss 8.8

Siemens OpenSSL Affecting Industrial Products

Siemens SINEMA Remote Connect Server <V3.1
affected: fixed in V3.1 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 ICSA-23-278-01 updated 2023-10-05 cvss 8.8

Hitachi Energy AFS65x,AFF66x, AFS67x, and AFR67x Series Products

Hitachi Energy AFF66X FW <= 03.0.02 Hitachi Energy AFR677 Hitachi Energy AFS65X Hitachi Energy AFS66X-B Hitachi Energy AFS66X-S Hitachi Energy AFS67X

+2 more productsfewer

Hitachi Energy AFS660-C Hitachi Energy AFS670-V20

affected: vendor fix, mitigation “Hitachi energy recommends the following actions:” publisher.hitachienergy.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 18 mo ago (2025-04-23)

Exploit prediction

3.18% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD	2.0	6.8	AV:N/AC:M/Au:N/C:P/I:P/A:P
OSV	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected packages

ecosystem	package	affected	fixed in
julia	Expat_jll	<2.4.4+0	2.4.4+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-190 Integer Overflow or Wraparound

References

github.com /libexpat/libexpat/pull/539
third-party-advisory, web
cert-portal.siemens.com /productcert/pdf/ssa-484086.pdf
patch, third-party-advisory, web
debian.org /security/2022/dsa-5073
vendor-advisory, third-party-advisory, web
security.gentoo.org /glsa/202209-24
vendor-advisory, third-party-advisory, web
openwall.com /lists/oss-security/2022/01/17/3
mailing-list, third-party-advisory, web
tenable.com /security/tns-2022-05
third-party-advisory, web
cert-portal.siemens.com /productcert/html/ssa-484086.html
cert-portal.siemens.com /productcert/html/ssa-398330.html

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.

Summary