CVE-2026-9739
Google Chrome SSE DNS Rebinding
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.
INFO
Published Date :
May 27, 2026, 9:38 p.m.
Last Modified :
May 27, 2026, 9:38 p.m.
Remotely Exploit :
Yes !
Source :
Affected Products
The following products are affected by CVE-2026-9739
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | CRITICAL | 14ed7db2-1595-443d-9d34-6215bf890778 |
Solution
- Remove the hardcoded 'Access-Control-Allow-Origin: *' header.
- Ensure only allowed origins are permitted.
- Update SSE initialization handler.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-9739 vulnerability anywhere in the article.