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Fencer Vulns
critical 9.8

CVE-2022-25235 json

`xmltok_impl.c` in Expat (aka libexpat) before 2.4.5 lacks certain validation of encoding, such as...

published 2022-02-16 4 y ago modified 2026-10-14 25 d ago also EUVD-2022-29933 , JLSEC-2025-52

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
5.0%
EPSS 5.0% chance of exploitation in 30 days, percentile 92%
public exploits
0
none known

Summary

xmltok_impl.c in Expat (aka libexpat) before 2.4.5 lacks certain validation of encoding, such as checks for whether a UTF-8 character is valid in a certain context.

Patch / fix

  • julia Expat_jll 2.4.8+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 2.4.5-1

debian advisories DEBIAN-CVE-2022-25235

  • expat Ubuntu 18.04 LTS 2.2.5-3ubuntu0.4
  • expat Ubuntu 20.04 LTS 2.2.9-1ubuntu0.2
  • firefox Ubuntu 22.04 LTS 1:1snap1-0ubuntu1
  • libxmltok Ubuntu 24.04 LTS 1.2-4.1ubuntu1
  • ayttm Ubuntu Pro 16.04 LTS 0.6.3-3ubuntu0.1~esm1
  • coin3 Ubuntu Pro 14.04 LTS 3.1.4~abc9f50-4ubuntu2+esm2
  • coin3 Ubuntu Pro 16.04 LTS 3.1.4~abc9f50+dfsg1-1ubuntu0.1~esm2
  • coin3 Ubuntu Pro 18.04 LTS 3.1.4~abc9f50+dfsg3-2ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2022-25235

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
  • redhat-virtualization-host RHEL 7 4.3.22-20220330.1.el7_9
  • redhat-virtualization-host-image-update RHEL 7 4.3.22-20220330.1.el7_9
  • mingw-expat RHEL 8 2.4.8-1.el8
  • mingw32-expat RHEL 8 2.4.8-1.el8
  • mingw64-expat RHEL 8 2.4.8-1.el8
  • thunderbird RHEL 8 91.7.0-2.el8_5
  • thunderbird RHEL 7 91.7.0-2.el7_9

red hat advisories RHBA-2022:4046RHSA-2022:1263RHSA-2022:7811RHSA-2022:0847RHSA-2022:1309RHSA-2022:0845

  • expat SLE Module for Basesystem 15 SP4, openSUSE Leap 15.4 2.4.4-150400.3.6.9
  • expat SLES 11 SP4-LTSS, SLE Point of Sale 11 SP3 2.0.1-88.42.18.1
  • expat SLES for SAP 15 SP2, SLES for SAP 15 SP1, SLES for SAP 15 +20 more 2.2.5-3.15.1
  • expat SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +11 more 2.1.0-21.18.1

suse advisories SUSE-SU-2022:2294-1SUSE-SU-2022:14903-1SUSE-SU-2022:0713-1SUSE-SU-2022:0698-1

  • expat openSUSE Tumbleweed 2.4.6-1.1
  • expat openSUSE Leap 15.3 2.2.5-3.15.1

opensuse advisories openSUSE-SU-2024:11866-1openSUSE-SU-2022:0713-1

  • mingw32-expat AlmaLinux 8 2.4.8-1.el8
  • mingw64-expat AlmaLinux 8 2.4.8-1.el8
  • xmlrpc-c-c++ AlmaLinux 8 1.51.0-5.el8_5.1
  • xmlrpc-c-client++ AlmaLinux 8 1.51.0-5.el8_5.1
  • expat AlmaLinux 8 2.2.5-8.el8_6.2
  • thunderbird AlmaLinux 8 91.7.0-2.el8_5.alma
  • thunderbird AlmaLinux 8 91.7.0-2.el8_5.alma.plus
  • firefox AlmaLinux 8 91.7.0-3.el8_5.alma

almalinux advisories ALSA-2022:7811ALSA-2022:1643ALSA-2022:0951ALSA-2022:0845ALSA-2022:0818

  • xmlrpc-c Rocky Linux 8 1.51.0-5.el8_5.1
  • expat Rocky Linux 8 2.2.5-4.el8_5.3
  • thunderbird Rocky Linux 8 91.7.0-2.el8_5
  • firefox Rocky Linux 8 91.7.0-3.el8_5

rocky linux advisories RLSA-2022:1643RLSA-2022:0951RLSA-2022:0845RLSA-2022:0818

  • expat Alpine 3.12 2.2.10-r2
  • expat Alpine 3.13 2.2.10-r4
  • expat Alpine 3.24, Alpine 3.23, Alpine 3.22 +8 more 2.4.5-r0

alpine advisories ALPINE-CVE-2022-25235

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 2.4.8-1

azure linux advisories AZL-8603

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-2022-25235 updated cvss 9.8

expat: Malformed 2- and 3-byte UTF-8 sequences can lead to arbitrary code execution

  • Red Hat Enterprise Linux 8 firefox, thunderbird
    affected: workaround, no fix available “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.”
  • Red Hat CodeReady Linux Builder (v. 8) mingw-expat 2.4.8-1.el8, mingw32-expat 2.4.8-1.el8, mingw64-expat 2.4.8-1.el8, xmlrpc-c-c++ 1.51.0-5.el8_5.1, xmlrpc-c-client++ 1.51.0-5.el8_5.1
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:1643
  • Red Hat CodeReady Linux Builder EUS (v. 8.2) xmlrpc-c-c++ 1.51.0-5.el8_2.1, xmlrpc-c-client++ 1.51.0-5.el8_2.1
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:1540
  • Red Hat Enterprise Linux AppStream (v. 8) firefox 91.7.0-3.el8_5, thunderbird 91.7.0-2.el8_5
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:0818
  • 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 “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHBA-2022:4046
  • Red Hat Enterprise Linux AppStream E4S (v. 8.1) firefox 91.7.0-3.el8_1, thunderbird 91.7.0-2.el8_1
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:0815
  • Red Hat Enterprise Linux AppStream EUS (v. 8.2) firefox 91.7.0-3.el8_2, thunderbird 91.7.0-2.el8_2
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:0816
  • Red Hat Enterprise Linux AppStream EUS (v.8.4) firefox 91.7.0-3.el8_4, thunderbird 91.7.0-2.el8_4
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:0817
show 14 more
  • Red Hat Enterprise Linux BaseOS (v. 8) expat 2.2.5-4.el8_5.3, xmlrpc-c 1.51.0-5.el8_5.1, xmlrpc-c-client 1.51.0-5.el8_5.1
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:0951
  • Red Hat Enterprise Linux BaseOS (v. 9) expat 2.2.10-12.el9_0
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHBA-2022:4046
  • Red Hat Enterprise Linux BaseOS E4S (v. 8.1) expat 2.2.5-3.el8_1.1, xmlrpc-c 1.51.0-5.el8_1.1, xmlrpc-c-client 1.51.0-5.el8_1.1
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:1068
  • Red Hat Enterprise Linux BaseOS EUS (v. 8.2) expat 2.2.5-3.el8_2.2, xmlrpc-c 1.51.0-5.el8_2.1, xmlrpc-c-client 1.51.0-5.el8_2.1
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:1070
  • Red Hat Enterprise Linux BaseOS EUS (v.8.4) expat 2.2.5-4.el8_4.2, xmlrpc-c 1.51.0-5.el8_4.1, xmlrpc-c-client 1.51.0-5.el8_4.1
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:1012
  • Red Hat Enterprise Linux Client (v. 7) expat 2.1.0-14.el7_9, firefox 91.7.0-3.el7_9, thunderbird 91.7.0-2.el7_9 Red Hat Enterprise Linux Client Optional (v. 7) firefox 91.7.0-3.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
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:1069
  • Red Hat Enterprise Linux CRB EUS (v.8.4) xmlrpc-c-c++ 1.51.0-5.el8_4.1, xmlrpc-c-client++ 1.51.0-5.el8_4.1
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:1644
  • Red Hat Enterprise Linux Server (v. 6 ELS) expat 2.0.1-14.el6_10
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:1309
  • Red Hat Enterprise Linux Server (v. 7) expat 2.1.0-14.el7_9, firefox 91.7.0-3.el7_9 Red Hat Enterprise Linux Server Optional (v. 7) firefox 91.7.0-3.el7_9, thunderbird 91.7.0-2.el7_9 Red Hat Enterprise Linux Workstation (v. 7) expat 2.1.0-14.el7_9, firefox 91.7.0-3.el7_9, thunderbird 91.7.0-2.el7_9 Red Hat Enterprise Linux Workstation Optional (v. 7) firefox 91.7.0-3.el7_9
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:1069
  • Red Hat JBoss Core Services
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:7144
  • Red Hat Virtualization 4 Hypervisor for RHEL 7 redhat-virtualization-host 4.3.22-20220330.1.el7_9, redhat-virtualization-host-image-update 4.3.22-20220330.1.el7_9
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:1263
  • Red Hat Virtualization 4 Hypervisor for RHEL 8 redhat-virtualization-host 4.4.10-202203211649_8.5, redhat-virtualization-host-image-update 4.4.10-202203211649_8.5
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:1053
  • Red Hat RHEL 7-based RHEV-H for RHEV 4 (build requirements) redhat-virtualization-host 4.3.22-20220330.1.el7_9, redhat-virtualization-host-image-update 4.3.22-20220330.1.el7_9
    fixed: vendor fix “There is no known mitigation other than restricting applications using the expat library from processing untrusted XML content. Please update the affected packages as soon as possible.” RHSA-2022:1263
  • Red Hat Enterprise Linux 9 firefox, xmlrpc-c, firefox-x11, thunderbird, xmlrpc-c-c++, xmlrpc-c-client, +1 more Red Hat Virtualization 4 Hypervisor for RHEL 8 elfutils 0.185-1.el8, elfutils-debuginfod-client 0.185-1.el8 Red Hat RHEL 7-based RHEV-H for RHEV 4 (build requirements) redhat-release-virtualization-host 4.3.22-1.el7ev, redhat-virtualization-host-productimg 4.3.22-1.el7, redhat-virtualization-host-image-update-placeholder 4.3.22-1.el7ev Red Hat RHEL 8-based RHEV-H for RHEV 4 (build requirements) redhat-release-virtualization-host 4.4.10-3.el8ev, redhat-release-virtualization-host-content 4.4.10-3.el8ev, redhat-virtualization-host-image-update-placeholder 4.4.10-3.el8ev
    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 9.8

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 cvss 9.8

Siemens OpenSSL Affecting Industrial Products

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 cvss 9.8

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 products
    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
yes
Technical impact
total
Assessed
18 mo ago

Exploit prediction

4.96% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P
OSV 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
julia Expat_jll
<2.4.8+0
2.4.8+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-116 Improper Encoding or Escaping of Output

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.