Vulnerability in @budibase/backend-core (CVE-2026-42239)
Summary
Vulnerability in @budibase/backend-core (CVE-2026-42239). Confidential information can be exposed externally. Exploitable via document.cookie. Mitigation: upgrade to 3.35.10 or later.
Original description
The description as published by the source.
Budibase is an open-source low-code platform. Prior to version 3.35.10, the budibase:auth cookie containing the JWT session token is set with httpOnly: false at packages/backend-core/src/utils/utils.ts:218. JavaScript can read this cookie via document.cookie. This means every XSS becomes a full account takeover — the attacker steals the JWT and has persistent access to the victim's account. The cookie also lacks secure: true (sent over plaintext HTTP) and sameSite attribute. This issue has been patched in version 3.35.10.
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-2026-42239 has been found in @budibase/backend-core.
Attackers can target a specific entry point like document.cookie over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 8.1/10.
What to do: upgrade @budibase/backend-core to 3.35.10 or later.
If unsure, ask your IT team or search "@budibase/backend-core CVE-2026-42239" on the vendor's site.
CVE-2026-42239 (@budibase/backend-core) — CWE-1004 / CVSS v3 8.1
Attack vector: remote (network-reachable)
Attack surface: document.cookie / sameSite / true / secure
Patched: 3.35.10 — 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.
A vulnerability (CWE-1004) exists in @budibase/backend-core. Attackers reach the vulnerable code path via document.cookie.
Check the vendor advisory for the affected versions of @budibase/backend-core. Attack surface: document.cookie / sameSite / true / secure.
Severity: High (CVSS 8.1/10). Confidential information can be exposed externally.
Update to 3.35.10.
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 '@budibase/backend-core' . 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 '@budibase/backend-core' . | 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
@budibase/backend-core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 @budibase/backend-core to 3.35.10ステージング環境で 3.35.10 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。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com
- web github.com