Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-82209

CVE-2026-82209HIGH

curl curl — domain-scoped PSL domain cookie

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  L  H  N    8.2   .0037   29.0     —

AFFECTED
  Product  Versions                                    Fixed
  curl     7.46.0 –                                    —
  curl     e77b5b7453c1e8ccd7ec0816890d98e2f392e465 –  —
  curl     8.21.0 –                                    —

TIMELINE
  Aug 28  Reserved by curl
  Sep 6   Published (CNA: curl)
  Sep 11  EXPLOIT PUBLISHED — CVE-2026-82209 (curl). Public exploit reference added.
  Sep 15  EXPLOIT PUBLISHED — CVE-2026-82209 (curl). Public exploit reference added.

CWE-201 · CNA: curl · CVSS v3.1 · 3 references · NVD status: Modified

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`).

Lifecycle

Complete event history — 4 events, chronological
Date	Event	Detail
August 28, 2026	Reserved	Reserved by curl
September 6, 2026	Published	Published (CNA: curl)
September 11, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-82209 (curl). Public exploit reference added.
September 15, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-82209 (curl). Public exploit reference added.

Affected

Affected products and packages — 3 rows
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
curl	curl	—	7.46.0	—
curl	curl	—	e77b5b7453c1e8ccd7ec0816890d98e2f392e465	—
curl	curl	—	8.21.0	—

Weaknesses

CWE-201

References (3)

https://curl.se/docs/CVE-2026-82209.html [Patch, Vendor Advisory]
https://curl.se/docs/CVE-2026-82209.json [Vendor Advisory]
https://hackerone.com/reports/3972385 [Exploit, Mitigation, Third Party Advisory]

Authoritative record: CVE-2026-82209 at cve.org

Vendors: curl

Weaknesses: CWE-201

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-82209 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.