CVE-2026-82209
Description
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`).
CVSS Base Scores
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Affected Products
| Vendor | Product | Version | Status |
|---|---|---|---|
| curl | curl | 7.46.0 | affected |
| curl | curl | 8.15.0 | affected |
| curl | curl | 8.17.0 | affected |
| curl | curl | 8.21.0 | affected |
| curl | curl | e77b5b7453c1e8ccd7ec0816890d98e2f392e465 | affected |
| curl | curl | 8.21.0 | affected |
| curl | curl | 8.20.0 | affected |
| curl | curl | 8.19.0 | affected |
| curl | curl | 8.18.0 | affected |
| curl | curl | 8.17.0 | affected |
| curl | curl | 8.16.0 | affected |
| curl | curl | 8.15.0 | affected |
| curl | curl | 8.14.1 | affected |
| curl | curl | 8.14.0 | affected |
| curl | curl | 8.13.0 | affected |
| curl | curl | 8.12.1 | affected |
| curl | curl | 8.12.0 | affected |
| curl | curl | 8.11.1 | affected |
| curl | curl | 8.11.0 | affected |
| curl | curl | 8.10.1 | affected |
| curl | curl | 8.10.0 | affected |
| curl | curl | 8.9.1 | affected |
| curl | curl | 8.9.0 | affected |
| curl | curl | 8.8.0 | affected |
| curl | curl | 8.7.1 | affected |
| curl | curl | 8.7.0 | affected |
| curl | curl | 8.6.0 | affected |
| curl | curl | 8.5.0 | affected |
| curl | curl | 8.4.0 | affected |
| curl | curl | 8.3.0 | affected |
| curl | curl | 8.2.1 | affected |
| curl | curl | 8.2.0 | affected |
| curl | curl | 8.1.2 | affected |
| curl | curl | 8.1.1 | affected |
| curl | curl | 8.1.0 | affected |
| curl | curl | 8.0.1 | affected |
| curl | curl | 8.0.0 | affected |
| curl | curl | 7.88.1 | affected |
| curl | curl | 7.88.0 | affected |
| curl | curl | 7.87.0 | affected |
| curl | curl | 7.86.0 | affected |
| curl | curl | 7.85.0 | affected |
| curl | curl | 7.84.0 | affected |
| curl | curl | 7.83.1 | affected |
| curl | curl | 7.83.0 | affected |
| curl | curl | 7.82.0 | affected |
| curl | curl | 7.81.0 | affected |
| curl | curl | 7.80.0 | affected |
| curl | curl | 7.79.1 | affected |
| curl | curl | 7.79.0 | affected |
| curl | curl | 7.78.0 | affected |
| curl | curl | 7.77.0 | affected |
| curl | curl | 7.76.1 | affected |
| curl | curl | 7.76.0 | affected |
| curl | curl | 7.75.0 | affected |
| curl | curl | 7.74.0 | affected |
| curl | curl | 7.73.0 | affected |
| curl | curl | 7.72.0 | affected |
| curl | curl | 7.71.1 | affected |
| curl | curl | 7.71.0 | affected |
| curl | curl | 7.70.0 | affected |
| curl | curl | 7.69.1 | affected |
| curl | curl | 7.69.0 | affected |
| curl | curl | 7.68.0 | affected |
| curl | curl | 7.67.0 | affected |
| curl | curl | 7.66.0 | affected |
| curl | curl | 7.65.3 | affected |
| curl | curl | 7.65.2 | affected |
| curl | curl | 7.65.1 | affected |
| curl | curl | 7.65.0 | affected |
| curl | curl | 7.64.1 | affected |
| curl | curl | 7.64.0 | affected |
| curl | curl | 7.63.0 | affected |
| curl | curl | 7.62.0 | affected |
| curl | curl | 7.61.1 | affected |
| curl | curl | 7.61.0 | affected |
| curl | curl | 7.60.0 | affected |
| curl | curl | 7.59.0 | affected |
| curl | curl | 7.58.0 | affected |
| curl | curl | 7.57.0 | affected |
| curl | curl | 7.56.1 | affected |
| curl | curl | 7.56.0 | affected |
| curl | curl | 7.55.1 | affected |
| curl | curl | 7.55.0 | affected |
| curl | curl | 7.54.1 | affected |
| curl | curl | 7.54.0 | affected |
| curl | curl | 7.53.1 | affected |
| curl | curl | 7.53.0 | affected |
| curl | curl | 7.52.1 | affected |
| curl | curl | 7.52.0 | affected |
| curl | curl | 7.51.0 | affected |
| curl | curl | 7.50.3 | affected |
| curl | curl | 7.50.2 | affected |
| curl | curl | 7.50.1 | affected |
| curl | curl | 7.50.0 | affected |
| curl | curl | 7.49.1 | affected |
| curl | curl | 7.49.0 | affected |
| curl | curl | 7.48.0 | affected |
| curl | curl | 7.47.1 | affected |
| curl | curl | 7.47.0 | affected |
| curl | curl | 7.46.0 | affected |
Credits
- Stanislav Fort (Aisle Research)(finder)
- Daniel Stenberg(remediation developer)

