CVE-2026-82209
Publication date 6 September 2026
Last updated 25 September 2026
Ubuntu priority
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`).
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| curl | 26.04 LTS resolute |
Fixed 8.18.0-1ubuntu2.7
|
| 24.04 LTS noble |
Fixed 8.5.0-2ubuntu10.15
|
|
| 22.04 LTS jammy |
Fixed 7.81.0-1ubuntu1.29
|
|
| 20.04 LTS focal |
Fixed 7.68.0-1ubuntu2.25+esm9
|
|
| 18.04 LTS bionic |
Fixed 7.58.0-2ubuntu3.24+esm14
|
|
| 16.04 LTS xenial |
Not affected
|
|
| 14.04 LTS trusty |
Not affected
|
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charlescochran
The curl advisory says >=7.46.0 is affected, but Xenial's version of curl was compiled without PSL enabled, so this issue only affected Bionic and later.
Severity score breakdown
CVSS version: CVSS v3.0
Base score
8.2 · High
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
References
Related Ubuntu Security Notices (USN)
- USN-8820-1
- curl vulnerabilities
- 24 September 2026