High 7.5Published Jan 1, 2026

CVE-2026-21428cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library.

Updated under an hour ago (2026-10-19 08:23 UTC)

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Every CVE for yhirose cpp-httplib

Exploited in the last 30 days

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to version 0.30.0, the ``write_headers`` function does not check for CR & LF characters in user supplied headers, allowing untrusted header value to escape header lines. This vulnerability allows attackers to add extra headers, modify request body unexpectedly & trigger an SSRF attack. When combined with a server that supports http1.1 pipelining (springboot, python twisted etc), this can be used for server side request forgery (SSRF). Version 0.30.0 fixes this issue.

CVSS: 7.5 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Weakness (CWE): CWE-93
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Not given
NVD analysis: Analyzed
Record last updated: Jun 17, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

yhirose cpp-httplib yhirose:cpp-httplib	before 0.30.0	NVD

References

https://github.com/yhirose/cpp-httplib/commit/98048a033a532ff22320ce1d11789f8d5710dfcdpatch
https://github.com/yhirose/cpp-httplib/releases/tag/v0.30.0product, release-notes
https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-wpc6-j37r-jcx7exploit, third-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.