CVE-2026-42239
HIGHDescription
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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:N
Exploit Intelligence
Low risk: more likely to be exploited than 21% of all known CVEs.
References
Related Vulnerabilities
Other CWE-1004 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2025-27223 | High | 7.5 | 2.1% | - | - |
| CVE-2020-27658 | High | 7.1 | 1.3% | - | Fix |
| CVE-2021-42115 | High | 8.1 | 1.2% | - | - |
| CVE-2019-8283 | Medium | 6.5 | 1.2% | - | Fix |
| CVE-2021-3706 | High | 7.5 | 1.1% | - | Fix |
| CVE-2022-25172 | Medium | 6.1 | 1.0% | - | - |
Common questions
How do I fix CVE-2026-42239?
Upgrade budibase to 3.35.10 or later.
Is CVE-2026-42239 being actively exploited?
Not that we know of. CVE-2026-42239 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.28% is the estimated probability that it will be exploited in the next 30 days. That is higher than 21% of all scored CVEs.
How severe is CVE-2026-42239?
CVE-2026-42239 has a CVSS v3 base score of 8.1, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-42239 affect?
Published advisories record a fix for budibase (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2026-42239
Markdown
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TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-04.