cvedb.io
CVE-2026-45372
CRITICAL · CVSS 9.9
EPSS exploitation probability: 0%
Published 2026-05-29T20:16:26.473 · Last modified 2026-06-17T10:51:58.747

Summary

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.

Affected products

yhirose — cpp-httplib

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.