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.
{
"cna_assigner": "VulnCheck",
"cwe_ids": [
"CWE-1236"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86257.json"
}