{"id":"UBUNTU-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":"2026-06-25T13:30:09.815388191Z","published":"2026-01-01T18:15:00Z","upstream":["CVE-2026-21428"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-21428"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-21428"},{"type":"REPORT","url":"https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-wpc6-j37r-jcx7"},{"type":"REPORT","url":"https://github.com/yhirose/cpp-httplib/commit/98048a033a532ff22320ce1d11789f8d5710dfcd"},{"type":"REPORT","url":"https://github.com/yhirose/cpp-httplib/releases/tag/v0.30.0"}],"affected":[{"package":{"name":"cpp-httplib","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/cpp-httplib?arch=source&distro=esm-apps%2Fjammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.9.9+ds-1","0.9.10+ds-1","0.10.1+ds-1","0.10.2+ds-1","0.10.3+ds-1","0.10.3+ds-1ubuntu0.1~esm1","0.10.3+ds-1ubuntu0.1~esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"libcpp-httplib0","binary_version":"0.10.3+ds-1ubuntu0.1~esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-21428.json"}},{"package":{"name":"cpp-httplib","ecosystem":"Ubuntu:Pro:24.04:LTS","purl":"pkg:deb/ubuntu/cpp-httplib?arch=source&distro=esm-apps%2Fnoble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.13.1+ds-1ubuntu1","0.14.3+ds-1","0.14.3+ds-1.1","0.14.3+ds-1.1build1","0.14.3+ds-1.1build2","0.14.3+ds-1.1ubuntu0.1~esm1","0.14.3+ds-1.1ubuntu0.1~esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"libcpp-httplib0.14t64","binary_version":"0.14.3+ds-1.1ubuntu0.1~esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-21428.json"}},{"package":{"name":"cpp-httplib","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/cpp-httplib?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.18.7-1","0.18.7-1ubuntu0.25.10.1","0.18.7-1ubuntu0.25.10.2"],"ecosystem_specific":{"binaries":[{"binary_version":"0.18.7-1ubuntu0.25.10.2","binary_name":"libcpp-httplib0.18"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-21428.json"}},{"package":{"name":"cpp-httplib","ecosystem":"Ubuntu:Pro:26.04:LTS","purl":"pkg:deb/ubuntu/cpp-httplib?arch=source&distro=esm-apps%2Fresolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.18.7-1","0.26.0+ds-2ubuntu2","0.26.0+ds-2ubuntu3","0.26.0+ds-2ubuntu3+esm1"],"ecosystem_specific":{"binaries":[{"binary_version":"0.26.0+ds-2ubuntu3+esm1","binary_name":"libcpp-httplib0.26"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-21428.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"},{"type":"Ubuntu","score":"medium"}]}