CVE-2021-39240
haproxy: does not ensure that the scheme and path portions of a URI have the expected characters
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · August 17, 2021
Updated · November 22, 2025
Description
A flaw was found in haproxy. An input validation flaw when processing HTTP/2 requests causes haproxy to not ensure that the scheme and path portions of a URI have the expected characters. This may cause specially crafted input to bypass implemented security restrictions. The highest threat from this vulnerability is confidentiality.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CWE-20 · Improper Input Validation