CVE-2026-55659 Grist: XSS through unsafe value interpolation in server-rendered pages
Attackers can inject scripts via document names or OAuth parameters to execute code in victims' sessions, potentially escalating privileges to owner level.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-55659?
CVE-2026-55659 is a high-severity cross-site scripting vulnerability in gristlabs grist-core, published on 10 Jul 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
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.
Which versions are affected by CVE-2026-55659?
How do I fix CVE-2026-55659?
No fix has been published for CVE-2026-55659 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-55659 being exploited?
There is no known exploitation of CVE-2026-55659 in the wild and no public exploit code.
Sources
Also known as GHSA-6qrq-h2h6-cw54.