budibase: Sensitive Cookie Without 'HttpOnly' Flag
CVE-2026-42239 is a high-severity sensitive cookie without 'httponly' flag vulnerability in budibase, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, but only if a user takes part, for example by opening a link or file. Affected budibase versions: < 3.35.10. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.28% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of budibase you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:N. Scored by CNA (github.com).
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Sensitive Cookie Without 'HttpOnly' Flag
The product uses a cookie to store sensitive information, but the cookie is not marked with the HttpOnly flag.
How developers prevent this class of flaw
- Leverage the HttpOnly flag when setting a sensitive cookie in a response.
More Sensitive Cookie Without 'HttpOnly' Flag vulnerabilities (CWE-1004)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- github.com/Budibase/budibase/security/advisories/GHSA-4f9j-vr4p-642rExploit, Mitigation
Patches and release notes
- github.com/Budibase/budibase/releases/tag/3.35.10Release Notes
Other vulnerabilities in budibase
- 7.7 High severity
- 8.5 High severity
- 8.4 High severity
- 7.1 High severity
- 7.1 High severity
- 7.6 High severity
Recent Sensitive Cookie Without 'HttpOnly' Flag vulnerabilities
- 8.8 High severity
- 7.5 High severity
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