CVE-2026-9739
Last modified
CVE-2026-9739 is a critical-severity vulnerability rated 9.4/10 on the CVSS scale. Vulnerable to DNS rebinding attacks when using SSE (http://b/499408790). During the beta phase, we implemented `allowed-origins` and `allowed-hosts` flags to align with MCP security guidelines. EPSS estimates a 0.28% chance of exploitation in the next 30 days.
Description
Vulnerable to DNS rebinding attacks when using SSE (http://b/499408790). During the beta phase, we implemented `allowed-origins` and `allowed-hosts` flags to align with MCP security guidelines. However, the hardcoded `Access-Control-Allow-Origin: *` header in the SSE initialization handler was inadvertently retained. This vulnerability specifically impacts users connecting via Toolbox using SSE under specification v2024-11-05.
Metrics
Weakness Enumeration
Affected Software
Source: CNA advisory (CVE.org). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| MCP Toolbox for Databases | < PR 3054 (Fix CORS bypass) |
References
Timeline
- Published
- Last Modified
- Status
- Awaiting Analysis
Frequently Asked Questions
What is CVE-2026-9739?
How severe is CVE-2026-9739?
How do I fix CVE-2026-9739?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-97365A vulnerability was determined in chonkie-inc littrs 0.6.1/0…6.3
- CVE-2026-97366A security flaw has been discovered in jhen0409 react-native…6.3
- CVE-2026-97368A weakness has been identified in chillzhuang SpringBlade up…6.3
- CVE-2026-9737During query planning when reading the sort pattern in raw B…7.1
- CVE-2026-9738The Print, PDF, Email by PrintFriendly plugin for WordPress …4.4
- CVE-2026-97387Rejected reason: This CVE is a duplicate of another CVE.
- CVE-2026-9740A vulnerability in MongoDB Server's BSON validation logic al…8.7
- CVE-2026-97404In OpenStack Zaqar before 22.0.2, WSGI transport mishandles …9.2
- CVE-2026-97407In the Linux kernel, the following vulnerability has been re…
- CVE-2026-97408In the Linux kernel, the following vulnerability has been re…
- CVE-2026-97409In the Linux kernel, the following vulnerability has been re…8.8
- CVE-2026-9741A bug in query analysis processing of the $vectorSearch aggr…7.1
Are you affected by CVE-2026-9739?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST