{"id":"UBUNTU-CVE-2026-19872","details":"HTML::FormHandler versions before 0.410000 for Perl allow cross-site scripting via a submitted value rendered unescaped in an error message. The wrappers and renderers that emit a form's errors interpolate the error string straight into HTML with no escaping. Two of the library's own messages, no_match and not_allowed, splice the submitted value into that string, and a failing type constraint puts the rejected value into the message it builds, which _apply_actions hands to add_error. A field declared with a check regexp, a check list or a type constraint reaches those messages, with no custom validator and no non-default configuration. Errors rendered through an application's own escaping template layer rather than the library's rendering roles are not affected. A request over the network that submits markup to such a field gets it back live inside the error span, running script in the victim's origin. Re-rendering a rejected value later gives the stored variant.","modified":"2026-09-16T14:00:42.907434917Z","published":"2026-09-08T20:17:00Z","upstream":["CVE-2026-19872"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-19872"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-19872"},{"type":"REPORT","url":"https://lists.security.metacpan.org/cve-announce/msg/43387502/"}],"affected":[{"package":{"name":"libhtml-formhandler-perl","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/libhtml-formhandler-perl?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.40057-1","0.40064-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libhtml-formhandler-perl","binary_version":"0.40064-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19872.json"}},{"package":{"name":"libhtml-formhandler-perl","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/libhtml-formhandler-perl?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.40067-1","0.40068-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libhtml-formhandler-perl","binary_version":"0.40068-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19872.json"}},{"package":{"name":"libhtml-formhandler-perl","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/libhtml-formhandler-perl?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.40068-1"],"ecosystem_specific":{"binaries":[{"binary_version":"0.40068-1","binary_name":"libhtml-formhandler-perl"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19872.json"}},{"package":{"name":"libhtml-formhandler-perl","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libhtml-formhandler-perl?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.40068-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libhtml-formhandler-perl","binary_version":"0.40068-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19872.json"}},{"package":{"name":"libhtml-formhandler-perl","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/libhtml-formhandler-perl?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.40068-2"],"ecosystem_specific":{"binaries":[{"binary_version":"0.40068-2","binary_name":"libhtml-formhandler-perl"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19872.json"}},{"package":{"name":"libhtml-formhandler-perl","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/libhtml-formhandler-perl?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.40068-2"],"ecosystem_specific":{"binaries":[{"binary_name":"libhtml-formhandler-perl","binary_version":"0.40068-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19872.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},{"type":"Ubuntu","score":"medium"}]}