{"id":"DEBIAN-CVE-2026-21428","details":"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.","modified":"2026-09-14T17:02:41.179920550Z","published":"2026-01-01T18:15:41.057Z","upstream":["CVE-2026-21428"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-21428"}],"affected":[{"package":{"name":"cpp-httplib","ecosystem":"Debian:12","purl":"pkg:deb/debian/cpp-httplib?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.11.4+ds-1","0.11.4+ds-1+deb12u1","0.11.4+ds-2","0.11.4+ds-3","0.13.1+ds-1","0.14.0+ds-1","0.14.1+ds-1","0.14.1+ds-2","0.14.2+ds-1","0.14.3+ds-1","0.14.3+ds-1.1","0.14.3+ds-1.1~exp1","0.15.3+ds-1","0.15.3+ds-2","0.15.3+ds-3","0.16.0+ds-1","0.16.3+ds-1","0.16.3+ds-2","0.18.0+ds-1","0.18.7-1","0.20.1+ds-3","0.25.0+ds-1","0.26.0+ds-2","0.41.0+ds-1","0.41.0+ds-2","0.41.0+ds-3","0.41.0+ds-3~bpo13+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-21428.json"}},{"package":{"name":"cpp-httplib","ecosystem":"Debian:13","purl":"pkg:deb/debian/cpp-httplib?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.18.7-1","0.18.7-1+deb13u1","0.20.1+ds-3","0.25.0+ds-1","0.26.0+ds-2","0.41.0+ds-1","0.41.0+ds-2","0.41.0+ds-3","0.41.0+ds-3~bpo13+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-21428.json"}},{"package":{"name":"cpp-httplib","ecosystem":"Debian:14","purl":"pkg:deb/debian/cpp-httplib?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.41.0+ds-3"}]}],"versions":["0.18.7-1","0.20.1+ds-3","0.25.0+ds-1","0.26.0+ds-2","0.41.0+ds-1","0.41.0+ds-2","0.41.0+ds-3~bpo13+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-21428.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"}]}