Cyber Resilience

CVE-2026-42239

Budibase ≤ 3.35.10

Public PoC
Published
07 May 2026
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v3.1 8.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:N
EPSS Score 0.0028 21th percentile
Risk Priority 52 floored blend · peak EPSS

Summary

CVE-2026-42239 is a high-severity Sensitive Cookie Without 'HttpOnly' Flag (CWE-1004) vulnerability in Budibase Budibase. Its CVSS base score is 8.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Steal Web Session Cookie (T1539); ranked at the 21th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SC-23 (Session Authenticity) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A02:2025 Security Misconfiguration

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)
CWE-1004

Related Threats

MITRE ATT&CK Enterprise Techniques

T1539 Steal Web Session Cookie Credential Access
An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-35218Same product: Budibase Budibase
CVE-2026-25737Same product: Budibase Budibase
CVE-2023-29010Same product: Budibase Budibase
CVE-2026-41428Same product: Budibase Budibase
CVE-2026-35216Same product: Budibase Budibase
CVE-2026-50137Same product: Budibase Budibase
CVE-2026-50136Same product: Budibase Budibase
CVE-2026-54350Same product: Budibase Budibase
CVE-2026-50132Same product: Budibase Budibase
CVE-2026-54352Same product: Budibase Budibase

Affected Assets

budibase
budibase
≤ 3.35.10

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SC-23 Session Authenticity good match

Proper implementation of session authenticity requires marking sensitive session cookies HttpOnly so that client scripts cannot access them.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Broad SDLC practices catch cookie-handling defects via standards/testing (mostly forward) yet remain too general to guarantee this narrow flag setting is always enforced (partial reverse).

PR.AT-02 partial match
prevents

Role-based training can reduce the chance developers introduce missing HttpOnly flags but supplies no enforcement or detection, leaving essentially all of the implementation flaw's risk intact.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect missing HttpOnly flags but does not prevent the weakness.

A.8.26 Application security requirements partial match
prevents

Application security requirements can mandate HttpOnly on sensitive cookies.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly require the HttpOnly flag for sensitive cookies.

References