How severe is CVE-2021-45960?

CVE-2021-45960 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-45960 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (90th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-45960?

CVE-2021-45960 primarily affects Libexpat Project Libexpat. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-45960?

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-2021-45960 published?

CVE-2021-45960 was published on 2022-01-01 and last updated on 2026-06-17.

CVE-2021-45960

CVE-2021-45960 is a high-severity vulnerability in Libexpat Project Libexpat with a CVSS 3.x base score of 8.8. 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-682.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 9.0
EPSS exploit prediction: 4% (90th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-682
Affected product: Libexpat Project Libexpat
Published: 2022-01-01
Last modified: 2026-06-17

Description

In Expat (aka libexpat) before 2.4.3, a left shift by 29 (or more) places in the storeAtts function in xmlparse.c can lead to realloc misbehavior (e.g., allocating too few bytes, or only freeing memory).

Frequently asked questions

What is CVE-2021-45960?: In Expat (aka libexpat) before 2.4.3, a left shift by 29 (or more) places in the storeAtts function in xmlparse.c can lead to realloc misbehavior (e.g., allocating too few bytes, or only freeing memory).
How severe is CVE-2021-45960?: CVE-2021-45960 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-45960 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (90th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-45960?: CVE-2021-45960 primarily affects Libexpat Project Libexpat. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-45960?: 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-2021-45960 published?: CVE-2021-45960 was published on 2022-01-01 and last updated on 2026-06-17.

References

Affected products (11)

cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*
cpe:2.3:a:tenable:nessus:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
cpe:2.3:a:siemens:sinema_remote_connect_server:*:*:*:*:*:*:*:*
cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:*
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:-:*:*:*:*:*:*:*

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