{"schemaVersion":3,"id":"CVE-2026-54163","aliases":["UBUNTU-CVE-2026-54163","DEBIAN-CVE-2026-54163","GHSA-rqq5-2gf9-4w4q"],"status":"published","duplicateOf":null,"title":null,"description":"secure_headers manages application of security headers with many safe defaults. Prior to 7.3.0, secure_headers builds the Content-Security-Policy value by stitching directives with ; separators, and build_sandbox_list_directive, build_media_type_list_directive, and build_report_to_directive interpolate caller-supplied strings without scrubbing ;, \\r, or \\n. When untrusted input reaches SecureHeaders.override_content_security_policy_directives or append APIs for :sandbox, :plugin_types, or :report_to, an attacker can inject a CSP directive such as script-src 'unsafe-inline' * before the legitimate script-src, enabling XSS reachability through these sinks or CSP report exfiltration. 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