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.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://curl.se/docs/CVE-2026-80255.html	Patch Vendor Advisory
https://curl.se/docs/CVE-2026-80255.json	Vendor Advisory
https://hackerone.com/reports/3972395	Exploit Mitigation Third Party Advisory
https://hackerone.com/reports/3972395	Exploit Mitigation Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-09-06 18:17

Updated : 2026-09-15 07:16

NVD link : CVE-2026-80255

Mitre link : CVE-2026-80255

CVE.ORG link : CVE-2026-80255

JSON object : View

Products Affected

haxx

curl

CWE

CWE-201

Insertion of Sensitive Information Into Sent Data

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