CVE-2026-82209
highWhen libpsl support is enabled, libcurl fails to enforce the Public Suffix List boundary check when processing a `Set-Cookie` header where the `Domain` attribu…
Vendor / product: Haxx — curl
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N Affected products
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
References
- https://curl.se/docs/CVE-2026-82209.html 2499f714-1537-4658-8207-48ae4bb9eae9
- https://curl.se/docs/CVE-2026-82209.json 2499f714-1537-4658-8207-48ae4bb9eae9
- https://hackerone.com/reports/3972385 2499f714-1537-4658-8207-48ae4bb9eae9
- https://hackerone.com/reports/3972385 134c704f-9b21-4f2e-91b3-4a467353bcc0