CVE-2026-25536 is a cross-client response data leak vulnerability affecting the MCP TypeScript SDK versions 1.10.0 through 1.25.3. This occurs when a single McpServer/Server and transport instance is reused across multiple client connections, particularly in stateless StreamableHTTPServerTransport deployments. The vulnerability has a CVSS score of 7.1 (High), indicating it can be exploited over a network with low complexity by a low-privileged attacker, leading to high confidentiality impact and low integrity impact. There is currently no evidence of active exploitation, public exploit code, or significant community discussion surrounding this CVE.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
>= 1.10.0, < 1.26.0CPE matchmatch criteria | cpe:2.3:a:lfprojects:mcp_typescript_sdk:*:*:*:*:*:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.3 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.
The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.