# CVE-2026-108259: Tina: Code injection via unescaped Git branch name in generated client source

> Attackers can inject code via crafted Git branch names in TinaCMS CLI, leading to arbitrary code execution during build processes.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Oct 2026
- **Updated:** 14 Oct 2026
- **Also known as:** GHSA-pwhx-cvv3-qj5c

## What is CVE-2026-108259?

CVE-2026-108259 is a high-severity code injection vulnerability in @tinacms cli, published on 9 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Tina is a headless content management system. Prior to 3.0.0, @tinacms/cli reads Git branch values from VERCEL_GIT_COMMIT_REF, GITHUB_BRANCH, or HEAD, incorporates the raw value into the API URL, and interpolates that URL into JavaScript string literals in packages/@tinacms/cli/src/next/codegen/index.ts and packages/@tinacms/cli/src/next/codegen/codegen/plugin.ts. A crafted Git-valid branch name containing a quote can terminate the generated string and inject an expression that executes when the generated client module is imported during a preview build. The injected code runs with the build process privileges and can read environment credentials, modify deployment artifacts, or make network requests. This issue is fixed in version 3.0.0.

Weakness: CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2026-108259?

2 open source packages ship an affected version, including @tinacms/cli.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@tinacms/cli` | npm | All versions | 3.0.0 |
| `@tinacms/cli` | npm | All versions | 3.0.0 |

## How do I fix CVE-2026-108259?

Upgrade @tinacms/cli to 3.0.0 or later.

## Is CVE-2026-108259 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-108259 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-108259 and fix it if it is affected.

What it is: CVE-2026-108259 is a high-severity code injection vulnerability in @tinacms cli, published on 9 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-108259 exists.

Affected packages and fixed versions:
- @tinacms/cli (npm): affected all versions; fixed in 3.0.0
- @tinacms/cli (npm): affected all versions; fixed in 3.0.0

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-2026-108259/ (Markdown: https://insights.sbomify.com/CVE-2026-108259/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-108259
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-108259
- OSV: https://osv.dev/vulnerability/CVE-2026-108259

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-108259/
Summaries are generated and may contain mistakes; the official description above is the record.