CVE-2026-55665 DOM-based XSS in Grist via unsanitized links, enabling privilege escalation
Attackers can execute arbitrary JavaScript in victims' sessions via unsanitized links, enabling data access and privilege escalation to owner level.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-55665?
CVE-2026-55665 is a high-severity cross-site scripting vulnerability in gristlabs grist-core, published on 10 Jul 2026. An attacker can exploit it over the internet without logging in, 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, 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-55665?
How do I fix CVE-2026-55665?
No fix has been published for CVE-2026-55665 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-2026-55665 being exploited?
There is no known exploitation of CVE-2026-55665 in the wild and no public exploit code.
Sources
Also known as GHSA-7f6v-vghq-34xq.