{"id":"CVE-2026-12939","summary":"Newsletters \u003c= 4.15 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'link' Shortcode Attribute","details":"The Newsletters Lite plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'link' attribute of the post_thumbnail (and newsletters_post_thumbnail) shortcodes in versions up to and including 4.15. This is due to insufficient input sanitization and output escaping in the post_thumbnail() method in helpers/shortcode.php, which concatenates the user-controlled $link shortcode attribute directly into an href attribute without esc_url() or esc_attr(). This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.","modified":"2026-10-06T02:35:41.471274617Z","published":"2026-07-29T01:29:41.142Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/12xxx/CVE-2026-12939.json","unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"last_affected":"4.15"}]}],"cna_assigner":"Wordfence","cwe_ids":["CWE-79"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/12xxx/CVE-2026-12939.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-12939"},{"type":"WEB","url":"https://plugins.trac.wordpress.org/browser/newsletters-lite/tags/4.15/helpers/shortcode.php#L327"},{"type":"WEB","url":"https://plugins.trac.wordpress.org/browser/newsletters-lite/tags/4.15/helpers/shortcode.php#L337"},{"type":"WEB","url":"https://plugins.trac.wordpress.org/browser/newsletters-lite/tags/4.15/helpers/shortcode.php#L782"},{"type":"WEB","url":"https://plugins.trac.wordpress.org/browser/newsletters-lite/tags/4.15/includes/checkinit.php#L182"},{"type":"WEB","url":"https://plugins.trac.wordpress.org/changeset?reponame=&old=3621582%40newsletters-lite&new=3621582%40newsletters-lite"},{"type":"WEB","url":"https://www.wordfence.com/threat-intel/vulnerabilities/id/2ca8ab94-45b8-4705-b23b-dbc743572121?source=cve"}],"affected":[{"package":{"name":"newsletters-lite","ecosystem":"WordPress:Plugin"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"4.15"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-12939.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N"}]}