CVE•Published 2026-05-29•Modified 2026-06-01•1 article on news•6 live references•NVD data
CVE-2026-45372Yhirose · Cpp-httplib
Vulnerability data via NVD (ingested)
CVSS v3.1
9.9
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L
EPSS percentile
—
Weaknesses (CWE)
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.
Timeline
Published 2026-05-29
Modified 2026-06-01
External references
Search for exposed instances
Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).
Shodan · vuln tag0 hosts
vuln:CVE-2026-45372Hosts Shodan has explicitly fingerprinted as vulnerable.
Shodan · product
product:"Yhirose Cpp-httplib"All exposed Yhirose Cpp-httplib instances — cross-reference with the CVE's affected-version range.
Shodan · banner/body mention
http.html:"Cpp-httplib"HTTP body or banner mentions "Cpp-httplib" — catches deploys Shodan didn't identify as a product.
More intel sources (5)
Shodan report
vuln:CVE-2026-45372Country / ASN / product breakdown for the vuln query.
Censys
vulnerabilities.cve_id: CVE-2026-45372Censys host search filtered to this CVE id.
grep.app
CVE-2026-45372Public source-code mentions — fast PoC discovery.
GitHub code
CVE-2026-45372GitHub code search for direct mentions.
Google dork
"CVE-2026-45372" exploit -site:nvd.nist.govWrite-ups and news, NVD excluded.
Known PoCs on GitHub
No public proof-of-concept repositories found for CVE-2026-45372 on GitHub.