Security Vulnerabilities
The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. Prior to 1.7.6, the client-side and server-side GitHub OIDC flow is bound only to a global audience string, not to the specific registry instance being targeted. On the client side, the publisher always appends audience=mcp-registry when requesting the GitHub Actions ID token, regardless of the selected --registry URL. On the server side, the exchange endpoint validates only that same fixed audience and then derives publish permissions directly from repository_owner. As a result, a token legitimately obtained while interacting with one registry deployment remains acceptable to any other deployment that shares the same code and audience string. This vulnerability is fixed in 1.7.6.
CVSS Score
2.1
EPSS Score
0.0
Published
2026-05-14
ZITADEL is an open source identity management platform. From 2.71.11 to before 3.4.10 and 4.15.0, a vulnerability was discovered in Zitadel's LDAP identity provider implementation, which fails to properly escape user-provided usernames before incorporating them into LDAP search filters. This allows unauthenticated attackers to perform LDAP Filter Injection during the login process. While this vulnerability does not allow for a full authentication bypass, an attacker can use LDAP metacharacters (such as *, (, )) to perform blind LDAP injection. By observing the different failure (or success) responses, an attacker can systematically enumerate valid usernames and extract sensitive attribute data from the connected LDAP directory. This vulnerability is fixed in 3.4.10 and 4.15.0.
CVSS Score
7.5
EPSS Score
0.001
Published
2026-05-14
The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. Prior to 1.7.7, the public catalogue UI served at GET / (file internal/api/handlers/v0/ui_index.html) is vulnerable to stored cross-site scripting via the server.websiteUrl field of any published server.json. Server-side validation in internal/validators/validators.go (validateWebsiteURL) only checks that the URL parses, is absolute, and uses the https scheme; it does not reject quote characters. Client-side, the value is interpolated into a double-quoted href attribute via innerHTML, using a homegrown escapeHtml helper that performs the standard textContent → innerHTML round-trip. Per the HTML serialisation algorithm, that round-trip encodes only &, <, > and U+00A0 inside text nodes — it does not encode " or '. A literal " in websiteUrl therefore breaks out of the href attribute, allowing arbitrary on* event handlers to be appended to the same <a> element. The Content-Security-Policy on / is script-src 'self' 'unsafe-inline' https://cdn.tailwindcss.com, so the injected event handlers execute. Any user able to obtain a publish token (e.g. via POST /v0/auth/github-at with their own GitHub account, or POST /v0/auth/none on a deployment that has anonymous auth enabled) can plant a poisoned record visible to every visitor of the registry homepage. This vulnerability is fixed in 1.7.7.
CVSS Score
5.1
EPSS Score
0.0
Published
2026-05-14
The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. Prior to 1.7.7, the Registry's HTTP-based namespace verification (POST /v0/auth/http, POST /v0.1/auth/http) uses safeDialContext (internal/api/handlers/v0/auth/http.go:67-110) to refuse dialling private/internal addresses when fetching the well-known public-key file from a publisher-supplied domain. The blocklist (isBlockedIP, lines 125-133) relies entirely on Go stdlib's IsLoopback / IsPrivate / IsLinkLocalUnicast / IsMulticast / IsUnspecified plus a manual CGNAT range. None of these cover IPv6 6to4 (2002::/16), NAT64 (64:ff9b::/96 and 64:ff9b:1::/48 per RFC 8215), or deprecated site-local (fec0::/10) — all of which encode arbitrary IPv4 in the address bits and tunnel to RFC1918 / cloud-metadata services on dual-stack / NAT64-enabled hosts. This vulnerability is fixed in 1.7.7.
CVSS Score
6.3
EPSS Score
0.0
Published
2026-05-14
Use after free in Extensions in Google Chrome on Mac prior to 148.0.7778.168 allowed an attacker who convinced a user to install a malicious extension to execute arbitrary code via a crafted Chrome Extension. (Chromium security severity: Medium)
CVSS Score
8.8
EPSS Score
0.0
Published
2026-05-14
Integer overflow in Fonts in Google Chrome prior to 148.0.7778.168 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted HTML page. (Chromium security severity: Medium)
CVSS Score
8.8
EPSS Score
0.001
Published
2026-05-14
Out of bounds read in GPU in Google Chrome on Linux prior to 148.0.7778.168 allowed a remote attacker who had compromised the renderer process to leak cross-origin data via a crafted HTML page. (Chromium security severity: Medium)
CVSS Score
3.1
EPSS Score
0.0
Published
2026-05-14
Insufficient validation of untrusted input in Skia in Google Chrome prior to 148.0.7778.168 allowed a remote attacker who had compromised the renderer process to perform an out of bounds memory write via a crafted print file. (Chromium security severity: Medium)
CVSS Score
3.1
EPSS Score
0.0
Published
2026-05-14
Use after free in Mojo in Google Chrome prior to 148.0.7778.168 allowed a remote attacker to potentially perform a sandbox escape via a crafted HTML page. (Chromium security severity: Medium)
CVSS Score
9.6
EPSS Score
0.001
Published
2026-05-14
Use after free in GPU in Google Chrome prior to 148.0.7778.168 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted HTML page. (Chromium security severity: Medium)
CVSS Score
8.8
EPSS Score
0.001
Published
2026-05-14