CVE-2026-55665
HighCVSS 8.5Exploitation Probability (EPSS)
Low risk24th percentile - higher than 24% of all known CVEs
Summary
Grist prior to version 1.7.15 contained two cross-site scripting vulnerabilities where an attacker-controlled value reached a link's href without scheme validation, allowing JavaScript execution in the victim's context on a single click. On the account-selection page, the next parameter was used as the link target, and in document tours, the GristDocTour table's Link_URL column became a clickable button, enabling an editor to store a malicious URL.
Risk Assessment
An attacker can execute a script in the victim's authenticated session, allowing reading or modifying data, changing sharing settings and access rules, and escalating privileges to owner-level access.
Recommendation
Immediately upgrade Grist to version 1.7.15 or later, which fixes both XSS vulnerabilities.
Other vulnerabilities in Grist
See all- CVE-2026-55664Medium
In Grist prior to version 1.7.15, the GET /forms endpoint read table and column metadata without applying the document's access rules and did not check that the requested section was actually a form. A user with only partial read access, including public access on a publicly viewable document, could request the metadata of any widget and reveal table and column structure that access rules would otherwise hide, even in documents that contain no forms.
- CVE-2026-55659High
Grist is spreadsheet software using Python as its formula language. Prior to version 1.7.15, several server-rendered pages embedded user-controlled values without proper escaping, leading to cross-site scripting. On the main page, a document's name or description set by an editor is rendered for other users. On the OAuth2 end-of-flow page, the openerOrigin parameter is reflected back.
Original NVD description (English source)
Grist is spreadsheet software using Python as its formula language. Prior to 1.7.15, Grist contained two cross-site scripting vulnerabilities where an attacker-controlled value reached a link's href without scheme validation, so a javascript URL could run in a victim's Grist origin on a single click. On the account-selection page, /welcome/select-account used its next query parameter as the account buttons' link target. In document tours, the GristDocTour table's Link_URL column became a clickable button, allowing an editor of a shared document to store a javascript URL there that ran when another user opened the document and clicked the tour link. Because the script runs in the victim's authenticated session, it can call Grist APIs as the victim, reading or modifying data and changing sharing settings and access rules. A document editor could therefore escalate to owner-level access. This issue is fixed in version 1.7.15.