NocoDB is software for building databases as spreadsheets. Prior to 2026.05.1, an authenticated commenter could store HTML in row comments that executed as script when other users hovered over the comment in the expanded form view. The comment write paths persisted the raw comment body with no server‑side sanitisation; the expanded‑form sidebar then rendered the stored body and fed its data‑tooltip attribute to Tippy with allowHTML: true. Even when the editor stripped script tags at write time, attribute‑level payloads re‑entered the DOM as live HTML on hover, enabling a stored‑cross‑site‑scripting attack. This vulnerability is fixed in 2026.05.1.

The vulnerability affects installations of NocoDB prior to the 2026.05.1 release. Any user who can comment on rows is at risk and any viewer of commented rows, including administrators, may be impacted.

The CVSS score of 7.4 indicates a high severity. No EPSS score is currently available and the issue is not listed in the CISA KEV catalogue. The stored‑XSS attack requires authenticated comment write access and the victim’s browser interacting with the comment. Based on the description, it is inferred that the exploit only triggers when a user hovers over the comment, so the attacker would need a target to view the comment in the UI. Despite the need for a user interaction, the absence of server‑side filtering makes the flaw easily exploitable for any user with commenting rights.