Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Stored cross-site scripting in the MCP Registry catalogue UI (github.com/modelcontextprotocol/registry, versions before 1.7.7) lets a publisher plant script in the `websiteUrl` field of a server record. A user with a publish token can submit a crafted URL that breaks out of an HTML attribute, and the script runs for visitors who expand the entry on the registry homepage. Upgrade to version 1.7.7, which is the listed fix.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 5.1 | Medium | 4.0 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:N/SI:L/SA:L | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0017, the 6th percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:14 UTC First seen by agentprime
- 31 Oct 2026, 14:14 UTC Confirmed by OSV
Sources
- GitHub Advisory Database: GHSA-rqv2-m695-f8j4
- OSV: GHSA-rqv2-m695-f8j4
- github.com/modelcontextprotocol/registry/security/advisories/GHSA-rqv2-m695-f8j4
- nvd.nist.gov/vuln/detail/CVE-2026-44429
- github.com/modelcontextprotocol/registry/pull/1249
- github.com/modelcontextprotocol/registry/commit/78b7bbde07948049b916d76b4769faee461ff930
- github.com/modelcontextprotocol/registry
- github.com/modelcontextprotocol/registry/releases/tag/v1.7.7