Ghostfolio's PUT /api/v1/portfolio/holding/:dataSource/:symbol/tags endpoint fails to verify Access.permissions field when processing the Impersonation-Id header, allowing read-only access grantees to modify portfolio holding tags. Attackers with valid read-only share tokens can assign or remove tags on victim holdings, corrupting portfolio categorization and reports.
{
"cna_assigner": "VulnCheck",
"cwe_ids": [
"CWE-862"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59709.json"
}