{"cve":"CVE-2026-45372","nvd":{"published":"2026-05-29T20:16:26.473","modified":"2026-07-22T06:10:00.170","status":"Modified","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L","score":9.9},"cwes":["CWE-93","CWE-444"],"references":["https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-xjxg-64p4-vj4m","https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-xjxg-64p4-vj4m"],"products":["yhirose:cpp-httplib"],"source":"nvd","synced_at":"2026-10-19T22:37:48.043517290+00:00"},"epss":{"cve":"CVE-2026-45372","score":0.00295,"percentile":0.22148,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}