What is the CVSS score of CVE-2026-55659?

CVE-2026-55659 has a CVSS 3.1 base score of 7.7 (High). CVSS vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N. EPSS exploitation probability: 0.3%.

Which versions of Grist are affected by CVE-2026-55659?

Grist document collaboration platform versions prior to 1.7.15 are vulnerable to privilege escalation attacks that allow document editors to inject malicious code into document metadata.. A patch is available.

How to fix or mitigate CVE-2026-55659?

Within 24 hours: Inventory all Grist deployments and identify those running versions below 1.7.15. Within 7 days: Upgrade all affected Grist instances to version 1.7.15 or later and verify deployment success across all systems. Within 30 days: Audit document access logs and activity trails for the period when vulnerable versions were active to detect signs of exploitation.

Grist CVE-2026-55659

EUVD-2026-43044 HIGH

Cross-site Scripting (XSS) (CWE-79)

2026-07-10 GitHub_M

XSS Python Grist Core

7.7

CVSS 3.1 · Vendor: GitHub_M

Severity by source

Vendor (GitHub_M) PRIMARY

7.7 HIGH

AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N

vuln.today AI

8.7 HIGH

Editor access gives PR:L and reliable stored-XSS injection gives AC:L; a higher-privileged victim must open the doc (UI:R), script crosses the user boundary (S:C) enabling data read/modify (C:H/I:H), no availability impact.

3.1 AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

4.0 AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N

Primary rating from Vendor (GitHub_M).

CVSS VectorVendor: GitHub_M

Attack Vector

Network

Attack Complexity

High

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

None

Lifecycle Timeline

Patch available

Jul 10, 2026 - 22:02 EUVD

Analysis Generated

Jul 10, 2026 - 21:44 vuln.today

DescriptionCVE.org

Grist is spreadsheet software using Python as its formula language. Prior to 1.7.15, several server-rendered Grist pages embedded user-controlled values into the page and into inline scripts without fully escaping them, allowing cross-site scripting. On the main application page, a document's name or description, set by a document editor, is rendered into the page that other users load when opening the document. On the OAuth2 end-of-flow page, the openerOrigin request parameter was reflected back into the served page. Injected script runs in the victim's Grist origin and can act through the authenticated session, 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.

Articles & Coverage 1

News 6 New Python Vulnerabilities - 1 Critical, 5 High, 1 With POC Jul 11, 2026

AnalysisAI

Stored and reflected cross-site scripting in Grist (grist-core) prior to 1.7.15 lets a document editor inject script into a document's name or description that executes when higher-privileged users open the document, and lets attackers abuse the OAuth2 end-of-flow page's reflected openerOrigin parameter. Because the injected script runs in the victim's authenticated Grist origin, a mere document editor can read or modify data, alter sharing settings and access rules, and escalate to owner-level control. No public exploit identified at time of analysis; the issue is CWE-79 and is fixed upstream in the tagged 1.7.15 release.

Technical ContextAI

Grist is an open-source spreadsheet/database application from Grist Labs that uses Python as its formula language and serves several server-rendered pages. The root cause is CWE-79 (Improper Neutralization of Input During Web Page Generation): user-controlled values were embedded into HTML pages and into inline <script> blocks without full contextual escaping. Two sinks are named - the main application page renders a document's editor-supplied name/description into the page loaded by other users (stored/persistent XSS), and the OAuth2 end-of-flow page reflects the openerOrigin request parameter back into the served page (reflected XSS). Inline-script context is particularly dangerous because HTML-entity escaping alone is insufficient inside a script element, allowing breakout into executable JavaScript. The affected component per CPE is cpe:2.3:a:gristlabs:grist-core, i.e. the self-hosted grist-core codebase.

RemediationAI

Vendor-released patch: 1.7.15 - upgrade grist-core to version 1.7.15 or later, which adds full escaping of the affected values (see release https://github.com/gristlabs/grist-core/releases/tag/v1.7.15, commit 4ced8064b7ea0e1763d5a6a2588b22774ce7efbc, and advisory GHSA-6qrq-h2h6-cw54). If immediate upgrade is not possible, reduce exposure by limiting document-editor rights on shared documents to trusted users only (removing the injection vector for the name/description sink) and by restricting or fronting the OAuth2 end-of-flow endpoint so the openerOrigin parameter cannot be attacker-supplied to victims; these controls narrow but do not eliminate the flaw and may disrupt legitimate collaboration and SSO login flows, so they are stopgaps until 1.7.15 is deployed.