CVE-2026-45372

Publication date 29 May 2026

Last updated 6 June 2026


Ubuntu priority

Cvss 3 Severity Score

9.9 · Critical

Score breakdown

Description

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.44.0, when cpp-httplib's server parses an incoming request, it applies percent-decoding to every header value except Location and Referer. The validity check (is_field_value) is run before decoding, so encoded %0D%0A passes the check and is then expanded to a literal \r\n byte pair inside the stored header value. This vulnerability is fixed in 0.44.0.

Status

Package Ubuntu Release Status
cpp-httplib 26.04 LTS resolute
Needs evaluation
25.10 questing
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Needs evaluation

Severity score breakdown

Parameter Value
Base score 9.9 · Critical
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Changed
Confidentiality Low
Integrity impact High
Availability impact Low
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L

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