CVE-2026-80255
A `Set-Cookie:` header using tab (horizontal tab, ASCII code 9) instead of space (ascii code 32) immediately before the `Secure` attribute causes curl to store the cookie without its Secure flag. The cookie might then wrongfully be sent over plaintext HTTP on subsequent requests to the same host.
- Published Sep 6, 2026
- CVSS 7.5 high
- 0.5% chance of exploitation in the next 30 days (EPSS)
- Public exploit code is available
- A fix is available