A business‑logic flaw in the add‑stock handling of the Pharmacy Product Management System allows the quantity field to accept negative values. When submitted, these values are applied as reductions, causing the inventory count to decrease instead of increase. This corruption can lead to critical stock records being depleted, potentially disrupting supply chains and causing application instability.

The vulnerability affects Senior‑Walter Web‑Based Pharmacy Product Management System version 1.0. No other vendor or product versions are currently known to be impacted.

The flaw has a CVSS score of 7.5, indicating high severity, but its EPSS score is below 1 % and it is not listed in CISA’s KEV catalog, suggesting a low probability of widespread exploitation. The likely attack vector is a web‑application user interacting with the add‑stock form, either as an authorized operator or via an external user if the form is exposed publicly. Exploitation requires passing the form with a negative quantity; proper input validation would block this path.