CVE-2026-86257 [MEDIUM] – wger before 2.6 fails to sanitize first_name and last_name fields in the gym member TSV ex

wger before 2.6 fails to sanitize first_name and last_name fields in the gym member TSV export endpoint, allowing any gym member to inject spreadsheet formulas. Attackers can inject formulas like =HYPERLINK to exfiltrate admin data or execute code when admins open the exported file in Excel or LibreOffice Calc.