Insertion of Sensitive Information Into Sent Data in cURL - CVE-2026-80255
Published: September 2, 2026
Vulnerability identifier: #VU146679
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-80255
CWE-ID: CWE-201
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to improper cookie attribute handling in the Set-Cookie header processing logic when parsing a Set-Cookie header that uses a tab immediately before the Secure attribute. A remote attacker can send a specially crafted Set-Cookie header to disclose sensitive information.
The issue can cause a cookie to be stored without its Secure flag and then be sent over plaintext HTTP on subsequent requests to the same host.
Affected software
cURL
How to mitigate CVE-2026-80255
Install security update from vendor's website.
cURL - update to 8.22.0