Is CVE-2026-42239 in the CISA KEV catalog?

No. CVE-2026-42239 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-42239?

CVE-2026-42239 has a CVSS v3 base score of 8.1 (HIGH).

What is the EPSS score for CVE-2026-42239?

CVE-2026-42239 has an EPSS score of 0.28% (20th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-42239?

Upgrade budibase to 3.35.10 or later.

CVE & CISA-KEV Catalog

CVE-2026-42239

HIGH

8.1

CVSS v3

NVD

Description

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.

CWE-1004

How to fix

Remediation Available

budibaseNVD

Affected:< 3.35.10Fixed in:3.35.10CVE-2026-42239derived from NVD

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

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredHigh

User InteractionRequired

ScopeChanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:N

Exploit Intelligence

0.28%probability of exploitation in 30 days

20thpercentile

Low risk: more likely to be exploited than 20% of all known CVEs.

References

Patch1

github.com

Exploit1

github.com

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-2021-39210	Medium	6.5	1.0%	-	Fix

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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.