CVE-2026-82209

Summary

When libpsl support is enabled, libcurl fails to enforce the Public Suffix List boundary check when processing a Set-Cookie header where the Domain attribute explicitly matches an origin host that is itself a public suffix (e.g., Domain=co.uk set by co.uk).

Instead of coercing it into a strict host-only cookie, libcurl saves the cookie with wildcard domain scope (.co.uk). Consequently, the cookie is inappropriately included in subsequent outbound requests or HTTP redirects to arbitrary sibling subdomains under the same public suffix (e.g., attacker.co.uk).

Affected Software

VendorProductVersion RangeStatus
curlcurl8.21.0 <= 8.21.0affected
curlcurl8.20.0 <= 8.20.0affected
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

Weaknesses

  • CWE-201 Information Exposure Through Sent Data

References