CVE-2026-80255CWE-201

CVE-2026-80255

High · published September 6, 2026

CVSS v3.1
7.5
EPSS
0%
Percentile
40.3
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00478 · 40.3th percentile
Weakness
CWE-201 · Insertion of Sensitive Information Into Sent Data
Published
2026-09-06T22:17Z
Affected products (1)
ProductVersionsFixed in
haxx/curl≥ 8.13.0, < 8.22.08.22.0
References (4)
EPSS history
Timeline
  • 08 SEP 03:24Z
    EPSS moved — → 0%
    epss
  • 06 SEP 17:48Z
    secure cookie attribute bypass with tab
    cvelistv5