Red Hat CVE-2026-27978
MEDIUM
GHSA-mq59-m269-xvcx
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V3 - Web Frontend Security Anti-CSRF tokens, SameSite cookies
MITRE ATT&CK
1 technique across 1 tactic: Initial Access The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | An attacker can perform state-changing operations (password changes, fund transfers, data deletion) using the victim's authenticated session. |
| Exploit ScenarioDerived | An attacker hosts a malicious page that, when visited by an authenticated user, silently submits a forged request to the target application using the user's cookies. |
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Alert meAnalysisAIv1 – Mar 17, 2026
Server Action CSRF validation in Next.js incorrectly treats null origins from sandboxed contexts as missing origins, allowing attackers to bypass verification and trick victim browsers into executing state-changing actions with their credentials. This affects applications relying on origin checks for CSRF protection without additional safeguards. A patch is available that enforces strict origin validation unless null is explicitly allowlisted.
Earlier versions of this analysis (1)
RemediationAI
A vendor patch is available — apply it immediately. Implement anti-CSRF tokens for all state-changing operations. Use SameSite cookie attribute. Verify the Origin/Referer header on the server side.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in npm
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
Cross-Site Request Forgery forces authenticated users to perform unintended actions by tricking their browser into sending forged requests. This vulnerability is classified as Cross-Site Request Forgery (CSRF) (CWE-352).
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
Primary rating from GitHub Advisory.
CVSS VectorGitHub Advisory
Lifecycle Timeline
2DescriptionGitHub Advisory
Summary
origin: null was treated as a "missing" origin during Server Action CSRF validation. As a result, requests from opaque contexts (such as sandboxed iframes) could bypass origin verification instead of being validated as cross-origin requests.
Impact
An attacker could induce a victim browser to submit Server Actions from a sandboxed context, potentially executing state-changing actions with victim credentials (CSRF).
Patches
Fixed by treating 'null' as an explicit origin value and enforcing host/origin checks unless 'null' is explicitly allowlisted in experimental.serverActions.allowedOrigins.
Workarounds
If upgrade is not immediately possible:
- Add CSRF tokens for sensitive Server Actions.
- Prefer
SameSite=Stricton sensitive auth cookies. - Do not allow
'null'inserverActions.allowedOriginsunless intentionally required and additionally protected.
Blast Radius
ecosystem impact- 46 npm packages depend on next (44 direct, 2 indirect)
Ecosystem-wide dependent count for version 16.0.1.
Executive ViewAI
CVE-2026-27978 presents moderate security risk, a cross-site request forgery vulnerability rated CVSS 4.3. Users could be tricked into performing unintended actions. A patch is available and should be applied during regular vulnerability management.
Apply vendor patch. If patching is delayed: implement SameSite cookie attributes and anti-CSRF tokens.
Threat Intelligence Overview
NVD
CVE.org
EPSS
VulDB
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Cross-Site Request Forgery exploits the automatic credential inclusion behavior of web browsers.
Exploit-DB