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 |
|---|---|---|---|---|
| 6.9 | Medium | 4.0 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0024, the 15th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 15:16 UTC First seen by agentprime
- 31 Oct 2026, 15:16 UTC Confirmed by OSV
Sources
- GitHub Advisory Database: GHSA-rjr6-rcgv-9m7m
- OSV: GHSA-rjr6-rcgv-9m7m
- github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-rjr6-rcgv-9m7m
- nvd.nist.gov/vuln/detail/CVE-2026-63118
- github.com/modelcontextprotocol/ruby-sdk/commit/ba543083a7594e7892b29464b89091816446ff7a
- github.com/modelcontextprotocol/ruby-sdk
- github.com/modelcontextprotocol/ruby-sdk/releases/tag/v0.23.0