CVSS 3.1
9.9 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:LCVE-2026-45372
Critical (9.9) in yhirose cpp-httplib. EPSS 0.3% chance of exploitation in the next 30 days.
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.
Severity
- EPSS
- 0.3% chance of exploitation in the next 30 days; higher than 22% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-93, CWE-444
- Published
- Modified
- Record from
- the NVD, synced
Affected
- yhirose:cpp-httplib