01 Record

CVE-2022-25313

In Expat (aka libexpat) before 2.4.5, an attacker can trigger stack exhaustion in build_model via a large nesting depth in the DTD element.

MediumPUBLISHEDCNA: mitre

CNA base score6.5 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

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02 Description

In Expat (aka libexpat) before 2.4.5, an attacker can trigger stack exhaustion in build_model via a large nesting depth in the DTD element.

03 Exploitation and scoring

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

3.29% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 88.4% of scored records. A rank, not a probability.

NVD base score

6.5 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

NVD analysis status

Modified. NVD last modified this record on 2026-10-14.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published

2022-02-18 04:23Z4 YR AGO

Last updated

2026-10-14 16:11Z15 DAYS AGO

Reserved

2022-02-18

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Medium (CVSS 6.5)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Weaknesses

CWE-674Uncontrolled RecursionClass
CWE-776Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')Base

Data version

5.2

Document digest

07490a525c07b79175eec48e541f4891bec1414254426d8101a713d88afd2689

05 Affected products

VendorProductVersionsPlatforms

debiandebian_linuxNot specified—

fedoraprojectfedoraNot specified—

libexpat_projectlibexpatNot specified—

oraclehttp_serverNot specified—

oraclezfs_storage_appliance_kitNot specified—

redhatenterprise_linuxNot specified—

redhatjboss_core_servicesNot specified—

redhatrhel_ausNot specified—

redhatrhel_eus_long_lifeNot specified—

siemenssinema_remote_connect_serverNot specified—

06 References

github.comhttps://github.com/libexpat/libexpat/pull/558x_refsource_MISC
www.openwall.com[oss-security] 20220219 Expat 2.4.5 released, includes 5 security fixeshttp://www.openwall.com/lists/oss-security/2022/02/19/1mailing-listx_refsource_MLIST
www.debian.orgDSA-5085https://www.debian.org/security/2022/dsa-5085vendor-advisoryx_refsource_DEBIAN
lists.fedoraproject.orgFEDORA-2022-04f206996bhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3UFRBA3UQVIQKXTBUQXDWQOVWNBKLERU/vendor-advisoryx_refsource_FEDORA
lists.fedoraproject.orgFEDORA-2022-3d9d67f558https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y27XO3JMKAOMQZVPS3B4MJGEAHCZF5OM/vendor-advisoryx_refsource_FEDORA
lists.debian.org[debian-lts-announce] 20220307 [SECURITY] [DLA 2935-1] expat security updatehttps://lists.debian.org/debian-lts-announce/2022/03/msg00007.htmlmailing-listx_refsource_MLIST
www.oracle.comhttps://www.oracle.com/security-alerts/cpuapr2022.htmlx_refsource_MISC
security.netapp.comhttps://security.netapp.com/advisory/ntap-20220303-0008/x_refsource_CONFIRM
cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/pdf/ssa-484086.pdfx_refsource_CONFIRM
security.gentoo.orgGLSA-202209-24https://security.gentoo.org/glsa/202209-24vendor-advisoryx_refsource_GENTOO
cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/html/ssa-484086.html
cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/html/ssa-398330.html

07 Fixed in

AlmaLinux 8

expat
Fixed in 2.2.5-8.el8_6.2
expat-devel
Fixed in 2.2.5-8.el8_6.2
mingw32-expat
Fixed in 2.4.8-1.el8
mingw64-expat
Fixed in 2.4.8-1.el8

AlmaLinux 9

expat
Fixed in 2.2.10-12.el9_0.2
expat-devel
Fixed in 2.2.10-12.el9_0.2

CloudLinux 8

expat
Fixed in 2.2.5-8.el8_6.2
expat-devel
Fixed in 2.2.5-8.el8_6.2
mingw32-expat
Fixed in 2.4.8-1.el8
mingw64-expat
Fixed in 2.4.8-1.el8

Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.

CloudLinux 9

expat
Fixed in 2.2.10-12.el9_0.2
expat-devel
Fixed in 2.2.10-12.el9_0.2

Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.

Debian 12

expat
Fixed in 2.4.5-1
libxmltok
No fix yet

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

expat
Fixed in 2.4.5-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

expat
Fixed in 2.4.5-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.