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.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
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
Which versions are affected by CVE-2026-108259?
2 open source packages ship an affected version, including @tinacms/cli.
| Package | 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.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-108259 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-108259 exists.
Sources
Also known as GHSA-pwhx-cvv3-qj5c.