# 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.

- **Severity:** High 8.5 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **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 available:** No
- **Published:** 10 Jul 2026
- **Updated:** 14 Jul 2026
- **Also known as:** GHSA-7f6v-vghq-34xq

## 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 (Improper Neutralization of Input During Web Page Generation)

## 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.

## Is CVE-2026-55665 being exploited?

There is no known exploitation of CVE-2026-55665 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55665 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-55665 in the wild and no public exploit code.

Affected product: gristlabs grist-core. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-55665/ (Markdown: https://insights.sbomify.com/CVE-2026-55665/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55665
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55665
- OSV: https://osv.dev/vulnerability/CVE-2026-55665

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-55665/
Summaries are generated and may contain mistakes; the official description above is the record.