CVE
CVE-2026-45372
cpp-httplib: HTTP header value percent-decoding in server-side `parse_header` enables CRLF injection
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 (isfieldvalue) 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.
Package Versions Affected
Package Version
patch Availability
No items found.
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CVSS Version
Severity
Base Score
CVSS Version
Score Vector
C
H
U
9.9
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L
C
H
U
0
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L
C
H
U
-
Related Resources
No items found.
References
https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45372.json, https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-xjxg-64p4-vj4m, https://nvd.nist.gov/vuln/detail/CVE-2026-45372