CVE-2025-9086
Publication date 10 September 2025
Last updated 25 February 2026
Ubuntu priority
Description
1. A cookie is set using the `secure` keyword for `https://target` 2. curl is redirected to or otherwise made to speak with `http://target` (same hostname, but using clear text HTTP) using the same cookie set 3. The same cookie name is set - but with just a slash as path (`path=\"/\",`). Since this site is not secure, the cookie *should* just be ignored. 4. A bug in the path comparison logic makes curl read outside a heap buffer boundary The bug either causes a crash or it potentially makes the comparison come to the wrong conclusion and lets the clear-text site override the contents of the secure cookie, contrary to expectations and depending on the memory contents immediately following the single-byte allocation that holds the path. The presumed and correct behavior would be to plainly ignore the second set of the cookie since it was already set as secure on a secure host so overriding it on an insecure host should not be okay.
Read the notes from the security team
Why is this CVE low priority?
Curl developers have rated this as being low severity
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| curl | 25.10 questing |
Vulnerable
|
| 24.04 LTS noble |
Not affected
|
|
| 22.04 LTS jammy |
Not affected
|
|
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial |
Not affected
|
|
| 14.04 LTS trusty |
Not affected
|
Notes
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
7.5 · High
|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity impact | None |
| Availability impact | High |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
References
Related Ubuntu Security Notices (USN)
- USN-8062-1
- curl vulnerabilities
- 25 February 2026