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Findings

CVE-2021-22926

libcurl-using applications can ask for a specific client certificate to be used in a transfer.

Published Aug 5, 2021 · corrected/updated Oct 14, 2026 · haxx curl · evidence confidence high

libcurl-using applications can ask for a specific client certificate to be used in a transfer. This is done with the option ( with the command line tool).When libcurl is built to use the macOS native TLS library Secure Transport, an application can ask for the client certificate by name or with a file name - using the same option. If the name exists as a file, it will be used instead of by name.If the appliction runs with a current working directory that is writable by other users (like ), a malicious user can create a file name with the same name as the app wants to use by name, and thereby trick the application to use the file based cert instead of the one referred to by name making libcurl send the wrong client certificate in the TLS connection handshake.

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2021-22926 is a high public vulnerability record for haxx curl. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether haxx curl is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: haxx/curl; netapp/active iq unified manager; netapp/clustered data ontap; netapp/h300e firmware. Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: CVSS 7.5, EPSS 15.1%. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-295, CWE-840. Sources contributing to this record: cve_org, epss, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Not listed as known exploited in CISA KEV. Not in the CISA KEV catalog.

  • Patch and remediation

    No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Aug 5, 2021 · NIST NVD

    Detected

    libcurl-using applications can ask for a specific client certificate to be used in a transfer. This is done with the option ( with the command line tool).When libcurl is built to use the macOS native TLS library Secure Transport, an application can ask for the client certificate by name or with a file name - using the same option. If the name exists as a file, it will be used instead of by name.If

  2. Oct 14, 2026 · NIST NVD

    Updated

    libcurl-using applications can ask for a specific client certificate to be used in a transfer. This is done with the option ( with the command line tool).When libcurl is built to use the macOS native TLS library Secure Transport, an application can ask for the client certificate by name or with a file name - using the same option. If the name exists as a file, it will be used instead of by name.If

Affected

  • cpe haxx/curlversion unspecified
  • cpe netapp/active iq unified managerversion unspecified
  • cpe netapp/clustered data ontapversion unspecified
  • cpe netapp/h300e firmwareversion unspecified
  • cpe netapp/h300s firmwareversion unspecified
  • cpe netapp/hci management nodeversion unspecified
  • cpe netapp/oncommand insightversion unspecified
  • cpe netapp/oncommand workflow automationversion unspecified
  • cpe netapp/snapcenterversion unspecified
  • cpe oracle/mysql serverversion unspecified
  • cpe siemens/sinec infrastructure network servicesversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2021-22926

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-22926

    30-day exploitation probability 15.1%

    first.org
  • NIST NVDVulnerability recordCVE-2021-22926

    libcurl-using applications can ask for a specific client certificate to be used in a transfer. This is done with the option ( with the command line tool).When libcurl is built to use the macOS native TLS library Secure Transport, an application can ask f

    nvd.nist.gov

References