CVE-2026-46431 Algernon: Auto-refresh SSE event server sets Access-Control-Allow-Origin: *

Algernon is a small self-contained pure-Go web server. Prior to 1.17.7, the SSE event server's Access-Control-Allow-Origin response header was hardcoded to the wildcard regardless of the caller's Origin. Because EventSource does not preflight and does not send cookies, the wildcard is sufficient ...

CVE-2026-46430

Algernon is a small self-contained pure-Go web server. Prior to 1.17.7, the SSE event server bound to 0.0.0.0:5553 on Linux/macOS by default because the platform-dependent host default in engine/flags.go:39-46 set host = "" for non-Windows, and utils.JoinHostPort"", ":5553" resolves to ":5553"...

CVE-2026-46430 Algernon: Auto-refresh SSE event server binds to all interfaces by default on Linux/macOS

Algernon is a small self-contained pure-Go web server. Prior to 1.17.7, the SSE event server bound to 0.0.0.0:5553 on Linux/macOS by default because the platform-dependent host default in engine/flags.go:39-46 set host = "" for non-Windows, and utils.JoinHostPort"", ":5553" resolves to ":5553"...

EUVD-2026-31869

Algernon is a small self-contained pure-Go web server. Prior to 1.17.7, the SSE event server bound to 0.0.0.0:5553 on Linux/macOS by default because the platform-dependent host default in engine/flags.go:39-46 set host = "" for non-Windows, and utils.JoinHostPort"", ":5553" resolves to ":5553"...

CVE-2026-46431: Permissive Cross-domain Policy with Untrusted Domains

Algernon is a small self-contained pure-Go web server. Prior to 1.17.7, the SSE event server's Access-Control-Allow-Origin response header was hardcoded to the wildcard regardless of the caller's Origin. Because EventSource does not preflight and does not send cookies, the wildcard is sufficient ...

CVE-2026-46430: Exposure of Resource to Wrong Sphere

Algernon is a small self-contained pure-Go web server. Prior to 1.17.7, the SSE event server bound to 0.0.0.0:5553 on Linux/macOS by default because the platform-dependent host default in engine/flags.go:39-46 set host = "" for non-Windows, and utils.JoinHostPort"", ":5553" resolves to ":5553"...

CVE-2026-44214: Improper Neutralization of CRLF Sequences

eventsource-encoder encodes events as well-formed EventSource/Server Sent Event SSE messages. Prior to 1.0.2, eventsource-encoder does not sanitize the event or id fields of an EventSourceMessage before serializing them. An attacker who controls either field can inject arbitrary Server-Sent Event...

PT-2026-42629

Unauthenticated Cross-Origin MCP Tool Invocation via Empty Default Secret | Field | Value | | ---------------- | ----- | | Repository | Jovancoding/Network-AI | | Affected version | v5.4.4 commit c12686e181f231cf8d7bcf836a96d78f0f0877ac | Summary The MCP SSE server defaults to an empty secret...

PT-2026-45206

HTTP transports expose unauthenticated PowerShell control with wildcard CORS There is an issue in the SSE and Streamable HTTP transport modes. The default stdio mode is not affected, but the documented HTTP modes expose the MCP control plane without authentication and add wildcard CORS handling...

GHSA-GJ84-924C-48FX Algernon: Auto-refresh SSE event server binds to all interfaces by default on Linux/macOS

Summary The SSE event server bound to 0.0.0.0:5553 on Linux/macOS by default because the platform-dependent host default in engine/flags.go:39-46 set host = "" for non-Windows, and utils.JoinHostPort"", ":5553" resolves to ":5553" — a Go http.Server.Addr of ":5553" listens on every interface. On...

PT-2026-42208

Name of the Vulnerable Software and Affected Versions Algernon versions prior to 1.17.7 Description The SSE event server's Access-Control-Allow-Origin response header is hardcoded to the wildcard , regardless of the caller's Origin. Because EventSource does not perform a preflight request and doe...

PT-2026-44917

Summary When auto-refresh is enabled, Algernon spins up an SSE handler that streams a data: line for every filesystem event under the watched directory. The handler performs no authentication of any kind — no shared token, no cookie check against the permissions2 userstate, no IP allow-list, no...

CR Injection in SSE Encoder Enables Event Splitting via cow_sse:event/1

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PT-2026-42988

Summary A critical identity spoofing vulnerability in MCPHub allows any unauthenticated user to impersonate any other user — including administrators — on SSE Server-Sent Events and MCP transport endpoints. The server accepts a username from the URL path parameter and creates an internal user...

CVE-2026-44217

sse-channel is an SSE-implementation which can be used to any node.js http request/response stream. Prior to 4.0.1, implementations that allow user-provided values to be passed to event, retry or id fields are susceptible to event spoofing, where an attacker could inject arbitrary messages into t...

CVE-2026-44217

The CVE-2026-44217 entry affects the sse-channel SSE implementation used in Node.js streams. Prior to version 4.0.1, passing user-provided values to the event, retry, or id fields allows event spoofing, enabling injection of arbitrary SSE messages into the stream and potentially impacting consume...

CVE-2026-44217

sse-channel is an SSE-implementation which can be used to any node.js http request/response stream. Prior to 4.0.1, implementations that allow user-provided values to be passed to event, retry or id fields are susceptible to event spoofing, where an attacker could inject arbitrary messages into t...

CVE-2026-44217 sse-channel: SSE Injection via unsanitized event fields

sse-channel is an SSE-implementation which can be used to any node.js http request/response stream. Prior to 4.0.1, implementations that allow user-provided values to be passed to event, retry or id fields are susceptible to event spoofing, where an attacker could inject arbitrary messages into t...

CVE-2026-44217 sse-channel: SSE Injection via unsanitized event fields

sse-channel is an SSE-implementation which can be used to any node.js http request/response stream. Prior to 4.0.1, implementations that allow user-provided values to be passed to event, retry or id fields are susceptible to event spoofing, where an attacker could inject arbitrary messages into t...

sse-channel 注入漏洞

SSE-Channel is a server-push event channel tool developed by Espen Hovlandsdal, based on Node.js. Versions of SSE-Channel prior to 4.0.1 had an injection vulnerability. This vulnerability stemmed from implementations that allowed users to provide values passed into fields such as event, retry, or...