How severe is CVE-2021-46143?

CVE-2021-46143 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-46143 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-46143?

CVE-2021-46143 primarily affects Libexpat Project Libexpat. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-46143?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-46143 published?

CVE-2021-46143 was published on 2022-01-06 and last updated on 2026-06-17.

CVE-2021-46143

CVE-2021-46143 is a high-severity vulnerability in Libexpat Project Libexpat with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-190.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 6.8
EPSS exploit prediction: 4% (89th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-190
Affected product: Libexpat Project Libexpat
Published: 2022-01-06
Last modified: 2026-06-17

Description

In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overflow exists for m_groupSize.

Frequently asked questions

What is CVE-2021-46143?: In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overflow exists for m_groupSize.
How severe is CVE-2021-46143?: CVE-2021-46143 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-46143 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-46143?: CVE-2021-46143 primarily affects Libexpat Project Libexpat. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-46143?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-46143 published?: CVE-2021-46143 was published on 2022-01-06 and last updated on 2026-06-17.

References

Affected products (10)

cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*
cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:*
cpe:2.3:a:netapp:clustered_data_ontap:-:*:*:*:*:*:*:*
cpe:2.3:a:netapp:hci_baseboard_management_controller:h610c:*:*:*:*:*:*:*
cpe:2.3:a:netapp:hci_baseboard_management_controller:h610s:*:*:*:*:*:*:*
cpe:2.3:a:netapp:hci_baseboard_management_controller:h615c:*:*:*:*:*:*:*
cpe:2.3:a:netapp:oncommand_workflow_automation:-:*:*:*:*:*:*:*
cpe:2.3:a:netapp:solidfire_\&_hci_management_node:-:*:*:*:*:*:*:*
cpe:2.3:a:tenable:nessus:*:*:*:*:*:*:*:*
cpe:2.3:a:siemens:sinema_remote_connect_server:*:*:*:*:*:*:*:*

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Other CWE-190 (Integer Overflow or Wraparound) vulnerabilities

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