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Fencer Vulns
high 7.5

CVE-2024-28757 json

libexpat through 2.6.1 allows an XML Entity Expansion attack when there is isolated use of external...

published 2024-03-10 2 y ago modified 2026-10-15 25 d ago also EUVD-2024-25843 , JLSEC-2025-61

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.0%
EPSS 2.0% chance of exploitation in 30 days, percentile 80%
public exploits
0
none known

Summary

libexpat through 2.6.1 allows an XML Entity Expansion attack when there is isolated use of external parsers (created via XML_ExternalEntityParserCreate).

Patch / fix

  • julia Expat_jll 2.6.2+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 SINEC NMS V3.0
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • expat Debian 12 2.5.0-1+deb12u4
  • expat Debian 14, Debian 13 2.6.1-2

debian advisories DEBIAN-CVE-2024-28757

  • expat Ubuntu 22.04 LTS 2.4.7-1ubuntu0.3

ubuntu advisories UBUNTU-CVE-2024-28757

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 8 2.5.0-1.el8_10
  • expat RHEL 9 2.5.0-2.el9_4
  • expat RHEL 9 2.5.0-1.el9_3.1
  • expat RHEL 9.2 EUS 2.5.0-1.el9_2.1

red hat advisories RHSA-2025:21776RHBA-2024:2518RHSA-2024:3926RHSA-2024:1530

  • expat Linux Micro 6.1 2.7.1-slfo.1.1_1.1
  • expat Linux Micro 6.0 2.7.1-1.1
  • expat Linux Micro 6.0 2.5.0-3.1
  • expat SLE Module for Basesystem 15 SP5, SLE Micro 5.5, SLE Micro 5.4 +10 more 2.4.4-150400.3.17.1

suse advisories SUSE-SU-2025:20311-1SUSE-SU-2025:20207-1SUSE-SU-2025:20045-1SUSE-SU-2024:1129-2SUSE-SU-2024:1129-1

  • expat openSUSE Tumbleweed 2.6.2-1.1

opensuse advisories openSUSE-SU-2024:13779-1

  • expat AlmaLinux 8 2.5.0-1.el8_10
  • expat AlmaLinux 9 2.5.0-1.el9_3.1

almalinux advisories ALSA-2025:21776ALSA-2024:1530

  • expat Alpine 3.24, Alpine 3.23, Alpine 3.22 +6 more 2.6.2-r0

alpine advisories ALPINE-CVE-2024-28757

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 2.6.2-2
  • expat Azure Linux 3.0 2.6.2-1

azure linux advisories AZL-35841AZL-35880

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-2024-28757 updated cvss 7.5

expat: XML Entity Expansion

  • Red Hat Enterprise Linux AppStream (v. 9) expat-devel 2.5.0-2.el9_4, expat-devel 2.5.0-1.el9_3.1, expat-debuginfo 2.5.0-2.el9_4, expat-debuginfo 2.5.0-1.el9_3.1, expat-debugsource 2.5.0-2.el9_4, expat-debugsource 2.5.0-1.el9_3.1
    fixed: vendor fix RHSA-2024:1530
  • Red Hat Enterprise Linux AppStream EUS (v.9.2) expat-devel 2.5.0-1.el9_2.1, expat-debuginfo 2.5.0-1.el9_2.1, expat-debugsource 2.5.0-1.el9_2.1
    fixed: vendor fix RHSA-2024:3926
  • Red Hat Enterprise Linux BaseOS (v. 8) expat 2.5.0-1.el8_10
    fixed: vendor fix RHSA-2025:21776
  • Red Hat Enterprise Linux BaseOS (v. 9) expat 2.5.0-2.el9_4, expat 2.5.0-1.el9_3.1
    fixed: vendor fix RHSA-2024:1530
  • Red Hat Enterprise Linux BaseOS EUS (v.9.2) expat 2.5.0-1.el9_2.1
    fixed: vendor fix RHSA-2024:3926
  • Red Hat OpenShift Container Platform 4.13 rhcos 413.92.202604080111
    fixed: vendor fix RHSA-2026:7239
  • Red Hat OpenShift Container Platform 4.14 rhcos 414.92.202603110216
    fixed: vendor fix RHSA-2026:5087
  • Red Hat OpenShift Container Platform 4.15 rhcos 415.92.202603101737
    fixed: vendor fix RHSA-2026:4419
show 5 more
  • Red Hat OpenShift Container Platform 4.16 rhcos 416.94.202603112010
    fixed: vendor fix RHSA-2026:4465
  • Red Hat OpenShift Container Platform 4.17 rhcos 417.94.202603102246
    fixed: vendor fix RHSA-2026:4480
  • Red Hat OpenShift Container Platform 4.18 rhcos 418.94.202603021444
    fixed: vendor fix RHSA-2026:3876
  • Red Hat OpenShift Container Platform 4.19 rhcos 4.19.9.6.202604080618
    fixed: vendor fix RHSA-2026:7243
  • Red Hat Enterprise Linux 6 expat, compat-expat1 Red Hat Enterprise Linux 7 expat Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8
    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-25-259-02 updated cvss 6.5

Hitachi Energy RTU500 Series

  • Hitachi Energy RTU500 series CMU Firmware vers:RTU500_series_CMU_Firmware/>=13.7.1, <=13.7.6
    affected: vendor fix, mitigation

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

cisa ICSA-23-348-10 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
2 y ago

Exploit prediction

2.01% chance of exploitation in the next 30 days, higher than 80% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/libexpat/libexpat/issues/839 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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
<2.6.2+0
2.6.2+0

Affected products

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

Classification

Weakness
  • 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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.