Code Injection in @tinacms/cli (CVE-2026-108259)
Summary
Code injection in @tinacms/cli (CVE-2026-108259). Confidential information can be exposed externally. Exploitable via client.ts. Mitigation: upgrade to 3.0.0 or later.
Original description
The description as published by the source.
Summary
@tinacms/cli inserts the raw Git branch value into the generated client.ts source without escaping or encoding. A Git-valid branch name can close the string literal and inject an arbitrary JavaScript expression that executes when the consumer build imports the generated client module.
Affected component
- Source (branch read):
packages/@tinacms/cli/src/cmds/init/templates/config.tslines 155–172 — readsVERCEL_GIT_COMMIT_REF,GITHUB_BRANCH, orHEADintoconfig.branch - Transform (URL build):
packages/@tinacms/cli/src/next/codegen/index.tslines 219–253 —_createApiUrl()concatenates the raw branch into the API URL with noencodeURIComponent - Sink (template):
packages/@tinacms/cli/src/next/codegen/index.tslines 363–381 —genClient()interpolates the URL intourl: '${apiURL}' - Sibling sink:
packages/@tinacms/cli/src/next/codegen/codegen/plugin.tsline 55 —url: "${apiURL}"(same pattern, double quotes)
Root cause
The codegen template at index.ts:376 uses:
url: '${apiURL}'
where apiURL contains the raw branch name. No JSON.stringify, encodeURIComponent, or string-escape function is applied at any point in the pipeline. A single quote in the branch name closes the string literal and allows expression injection.
Payload
The following is a valid Git branch name (git check-ref-format accepts it):
x'+(globalThis.__TINA_PROBE='hit')+'
Generated source (sink)
When codege…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-108259 has been found in @tinacms/cli.
Attackers can target a specific entry point like client.ts over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 8.2/10.
What to do: upgrade @tinacms/cli to 3.0.0 or later.
If unsure, ask your IT team or search "@tinacms/cli CVE-2026-108259" on the vendor's site.
CVE-2026-108259 (@tinacms/cli) — CWE-94 / CVSS v3 8.2
Attack vector: remote (network-reachable) / no user interaction
Attack surface: client.ts / VERCEL_GIT_COMMIT_REF / GITHUB_BRANCH / HEAD
Patched: 3.0.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Arbitrary code execution (CWE-94) exists in @tinacms/cli. Attackers reach the vulnerable code path via client.ts.
Check the vendor advisory for the affected versions of @tinacms/cli. Attack surface: client.ts / VERCEL_GIT_COMMIT_REF / GITHUB_BRANCH / HEAD.
Severity: High (CVSS 8.2/10). Confidential information can be exposed externally.
Update to 3.0.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r '@tinacms/cli' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r '@tinacms/cli' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
@tinacms/cliを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade @tinacms/cli to 3.0.0ステージング環境で 3.0.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。