How severe is CVE-2021-22897?

CVE-2021-22897 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2021-22897 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-22897?

CVE-2021-22897 primarily affects Haxx Curl. In total, 24 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-22897?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-22897 published?

CVE-2021-22897 was published on 2021-06-11 and last updated on 2026-06-17.

CVE-2021-22897

CVE-2021-22897 is a medium-severity vulnerability in Haxx Curl with a CVSS 3.x base score of 5.3. 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-668.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 4.3
EPSS exploit prediction: 3% (86th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-668
Affected product: Haxx Curl
Published: 2021-06-11
Last modified: 2026-06-17

Description

curl 7.61.0 through 7.76.1 suffers from exposure of data element to wrong session due to a mistake in the code for CURLOPT_SSL_CIPHER_LIST when libcurl is built to use the Schannel TLS library. The selected cipher set was stored in a single "static" variable in the library, which has the surprising side-effect that if an application sets up multiple concurrent transfers, the last one that sets the ciphers will accidentally control the set used by all transfers. In a worst-case scenario, this weakens transport security significantly.

Frequently asked questions

What is CVE-2021-22897?: curl 7.61.0 through 7.76.1 suffers from exposure of data element to wrong session due to a mistake in the code for CURLOPT_SSL_CIPHER_LIST when libcurl is built to use the Schannel TLS library. The selected cipher set was stored in a single "static" variable in the library, which has the surprising side-effect that if an application sets up multiple concurrent transfers, the last one that sets the ciphers will accidentally control the set used by all transfers. In a worst-case scenario, this weakens transport security significantly.
How severe is CVE-2021-22897?: CVE-2021-22897 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-22897 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-22897?: CVE-2021-22897 primarily affects Haxx Curl. In total, 24 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-22897?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-22897 published?: CVE-2021-22897 was published on 2021-06-11 and last updated on 2026-06-17.

References

Affected products (24)

cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*
cpe:2.3:a:oracle:communications_cloud_native_core_binding_support_function:1.11.0:*:*:*:*:*:*:*
cpe:2.3:a:oracle:communications_cloud_native_core_network_function_cloud_native_environment:1.10.0:*:*:*:*:*:*:*
cpe:2.3:a:oracle:communications_cloud_native_core_network_repository_function:1.15.0:*:*:*:*:*:*:*
cpe:2.3:a:oracle:communications_cloud_native_core_network_repository_function:1.15.1:*:*:*:*:*:*:*
cpe:2.3:a:oracle:communications_cloud_native_core_network_slice_selection_function:1.8.0:*:*:*:*:*:*:*
cpe:2.3:a:oracle:communications_cloud_native_core_service_communication_proxy:1.15.0:*:*:*:*:*:*:*
cpe:2.3:a:oracle:essbase:*:*:*:*:*:*:*:*
cpe:2.3:a:oracle:mysql_server:*:*:*:*:*:*:*:*
cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:*
cpe:2.3:a:netapp:solidfire\,_enterprise_sds_\&_hci_storage_node:-:*:*:*:*:*:*:*
cpe:2.3:a:netapp:solidfire_\&_hci_management_node:-:*:*:*:*:*:*:*
cpe:2.3:o:netapp:solidfire_baseboard_management_controller_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:netapp:hci_compute_node_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:netapp:h300e_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:netapp:h300s_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:netapp:h410s_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:netapp:h500e_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:netapp:h500s_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:netapp:h700e_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:netapp:h700s_firmware:-:*:*:*:*:*:*:*
cpe:2.3:a:siemens:sinec_infrastructure_network_services:*:*:*:*:*:*:*:*
cpe:2.3:a:splunk:universal_forwarder:*:*:*:*:*:*:*:*
cpe:2.3:a:splunk:universal_forwarder:9.1.0:*:*:*:*:*:*:*

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