CVE-2026-59709: Ghostfolio - Unauthorized Portfolio Holding Tag Modification via Missing Permission Check

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-07 · updated 2026-10-25
Weakness: CWE-862

Description

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.

References

https://github.com/ghostfolio/ghostfolio
https://github.com/ghostfolio/ghostfolio/commit/697ef59e3b58bebc5c21a9e482e4f5643390f316
https://github.com/ghostfolio/ghostfolio/issues/7196
https://www.vulncheck.com/advisories/ghostfolio-unauthorized-portfolio-holding-tag-modification-via-missing-permission-check
https://github.com/ghostfolio/ghostfolio/issues/7196

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