CVE-2026-82209 Details
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`).
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Sep 8, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://hackerone.com/reports/3972385 | CISA-ADP | ExploitMitigationThird Party Advisory |
| https://curl.se/docs/CVE-2026-82209.html | curl | PatchVendor Advisory |
| https://curl.se/docs/CVE-2026-82209.json | curl | Vendor Advisory |
| https://hackerone.com/reports/3972385 | curl | ExploitMitigationThird Party Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-201 | Insertion of Sensitive Information Into Sent Data | CISA-ADP |
| CWE-201 | Insertion of Sensitive Information Into Sent Data | curl |
Affected Products
| Product | Versions |
|---|---|
| haxx curl | >= 7.46.0, < 8.22.0 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 15, 2026 | CVE Modified | curl |
| Sep 11, 2026 | Initial Analysis | [email protected] |
| Sep 8, 2026 | CVE Modified | CISA-ADP |
| Sep 6, 2026 | New CVE Received | curl |