CVE-2026-5773

Summary

libcurl might in some circumstances reuse the wrong connection for SMB(S) transfers.

libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead.

When reusing a connection a range of criteria must be met. Due to a logical error in the code, a network transfer operation that was requested by an application could wrongfully reuse an existing SMB connection to the same server that was using a different 'share' than the new subsequent transfer should.

This could in unlucky situations lead to the download of the wrong file or the upload of a file to the wrong place. When this happens, the same credentials are used and the server name is the same.

Affected Software

VendorProductVersion RangeStatus
curlcurl8.19.0 <= 8.19.0affected
curlcurl8.18.0 <= 8.18.0affected
curlcurl8.17.0 <= 8.17.0affected
curlcurl8.16.0 <= 8.16.0affected
curlcurl8.15.0 <= 8.15.0affected
curlcurl8.14.1 <= 8.14.1affected
curlcurl8.14.0 <= 8.14.0affected
curlcurl8.13.0 <= 8.13.0affected
curlcurl8.12.1 <= 8.12.1affected
curlcurl8.12.0 <= 8.12.0affected
curlcurl8.11.1 <= 8.11.1affected
curlcurl8.11.0 <= 8.11.0affected
curlcurl8.10.1 <= 8.10.1affected
curlcurl8.10.0 <= 8.10.0affected
curlcurl8.9.1 <= 8.9.1affected
curlcurl8.9.0 <= 8.9.0affected
curlcurl8.8.0 <= 8.8.0affected
curlcurl8.7.1 <= 8.7.1affected
curlcurl8.7.0 <= 8.7.0affected
curlcurl8.6.0 <= 8.6.0affected
curlcurl8.5.0 <= 8.5.0affected
curlcurl8.4.0 <= 8.4.0affected
curlcurl8.3.0 <= 8.3.0affected
curlcurl8.2.1 <= 8.2.1affected
curlcurl8.2.0 <= 8.2.0affected
curlcurl8.1.2 <= 8.1.2affected
curlcurl8.1.1 <= 8.1.1affected
curlcurl8.1.0 <= 8.1.0affected
curlcurl8.0.1 <= 8.0.1affected
curlcurl8.0.0 <= 8.0.0affected
curlcurl7.88.1 <= 7.88.1affected
curlcurl7.88.0 <= 7.88.0affected
curlcurl7.87.0 <= 7.87.0affected
curlcurl7.86.0 <= 7.86.0affected
curlcurl7.85.0 <= 7.85.0affected
curlcurl7.84.0 <= 7.84.0affected
curlcurl7.83.1 <= 7.83.1affected
curlcurl7.83.0 <= 7.83.0affected
curlcurl7.82.0 <= 7.82.0affected
curlcurl7.81.0 <= 7.81.0affected
curlcurl7.80.0 <= 7.80.0affected
curlcurl7.79.1 <= 7.79.1affected
curlcurl7.79.0 <= 7.79.0affected
curlcurl7.78.0 <= 7.78.0affected
curlcurl7.77.0 <= 7.77.0affected
curlcurl7.76.1 <= 7.76.1affected
curlcurl7.76.0 <= 7.76.0affected
curlcurl7.75.0 <= 7.75.0affected
curlcurl7.74.0 <= 7.74.0affected
curlcurl7.73.0 <= 7.73.0affected
curlcurl7.72.0 <= 7.72.0affected
curlcurl7.71.1 <= 7.71.1affected
curlcurl7.71.0 <= 7.71.0affected
curlcurl7.70.0 <= 7.70.0affected
curlcurl7.69.1 <= 7.69.1affected
curlcurl7.69.0 <= 7.69.0affected
curlcurl7.68.0 <= 7.68.0affected
curlcurl7.67.0 <= 7.67.0affected
curlcurl7.66.0 <= 7.66.0affected
curlcurl7.65.3 <= 7.65.3affected
curlcurl7.65.2 <= 7.65.2affected
curlcurl7.65.1 <= 7.65.1affected
curlcurl7.65.0 <= 7.65.0affected
curlcurl7.64.1 <= 7.64.1affected
curlcurl7.64.0 <= 7.64.0affected
curlcurl7.63.0 <= 7.63.0affected
curlcurl7.62.0 <= 7.62.0affected
curlcurl7.61.1 <= 7.61.1affected
curlcurl7.61.0 <= 7.61.0affected
curlcurl7.60.0 <= 7.60.0affected
curlcurl7.59.0 <= 7.59.0affected
curlcurl7.58.0 <= 7.58.0affected
curlcurl7.57.0 <= 7.57.0affected
curlcurl7.56.1 <= 7.56.1affected
curlcurl7.56.0 <= 7.56.0affected
curlcurl7.55.1 <= 7.55.1affected
curlcurl7.55.0 <= 7.55.0affected
curlcurl7.54.1 <= 7.54.1affected
curlcurl7.54.0 <= 7.54.0affected
curlcurl7.53.1 <= 7.53.1affected
curlcurl7.53.0 <= 7.53.0affected
curlcurl7.52.1 <= 7.52.1affected
curlcurl7.52.0 <= 7.52.0affected
curlcurl7.51.0 <= 7.51.0affected
curlcurl7.50.3 <= 7.50.3affected
curlcurl7.50.2 <= 7.50.2affected
curlcurl7.50.1 <= 7.50.1affected
curlcurl7.50.0 <= 7.50.0affected
curlcurl7.49.1 <= 7.49.1affected
curlcurl7.49.0 <= 7.49.0affected
curlcurl7.48.0 <= 7.48.0affected
curlcurl7.47.1 <= 7.47.1affected
curlcurl7.47.0 <= 7.47.0affected
curlcurl7.46.0 <= 7.46.0affected
curlcurl7.45.0 <= 7.45.0affected
curlcurl7.44.0 <= 7.44.0affected
curlcurl7.43.0 <= 7.43.0affected
curlcurl7.42.1 <= 7.42.1affected
curlcurl7.42.0 <= 7.42.0affected
curlcurl7.41.0 <= 7.41.0affected
curlcurl7.40.0 <= 7.40.0affected

Weaknesses

  • CWE-488 Exposure of Data Element to Wrong Session

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: yes
    • Technical Impact: partial

Additional References

References