Vulnerability · Published May 7, 2026 · Assigned by GitHub_M

CVE-2026-42239Budibase auth session cookies are set with httpOnly:false — any XSS can lead to full account takeover

High 8.1

In plain English

A high-severity security flaw in budibase from Budibase. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.3%top 79.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	@budibase/backend-core	3.35.10	GHSA-4f9j-vr4p-642r

Affected products (as reported)

Vendor	Product	Versions
Budibase	budibase	< 3.35.10

Weakness: CWE-1004 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:N

References

https://github.com/Budibase/budibase/security/advisories/GHSA-4f9j-vr4p-642r x_refsource_CONFIRM
https://github.com/Budibase/budibase/releases/tag/3.35.10 x_refsource_MISC