CVE
Missing authorization on the external management API in mcp-gateway-registry enables privilege escalation to registry administrator
Affects mcp-gateway-registry versions 1.0.9 through 1.24.7, where an authenticated low-privileged user can gain registry administrator rights. Fixed in 1.25.0.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 1.25.0
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Deployments running mcp-gateway-registry versions 1.0.9 through 1.24.7
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 17/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
Missing authorization in the external management API of the AWS mcp-gateway-registry product lets a remote attacker with a low-privilege account grant themselves the registry administrator role through a crafted group import request. Once they have that role, they can take administrative control of every registered gateway asset.
Read the original description
Missing authorization in the external management API in Amazon mcp-gateway-registry 1.0.9 through 1.24.7 might allow an authenticated remote user to assign the registry administrator scope to their own identity group and obtain administrative control of every registered gateway asset via a crafted group import request.
To remediate this issue, users should upgrade to version 1.25.0.
Who should check
Teams running mcp-gateway-registry versions 1.0.9 through 1.24.7, including any forked or derivative code of the registry
Not fixed by: A privileged group mapping created before upgrading keeps granting administrator access after the upgrade.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure8/25Specific setups only, reachable over the network
- Reach?/20Unknown. No tracked technology or package matched
- Severity8.8/10CVSS 8.8
- No patch0/5No signal
What would change the score
- Would score about 67 if added to CISA KEV
- Would score about 62 if CISA's SSVC rates exploitation active
- Would score about 24 if CISA's SSVC rates it automatable
What to do
Check whether your setup matches what the bug needs.
Deployments running mcp-gateway-registry versions 1.0.9 through 1.24.7Upgrade to a fixed version: 1.25.0.
Workaround: Limit POST /api/servers/groups/* and the other /api/servers/* mutation routes to trusted administrator identities at the ingress or proxy layer, or block them for non-admin callers.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-100307 (Missing authorization on the external management API in mcp-gateway-registry enables privilege escalation to registry administrator), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-100307 (entry last updated 2026-11-11):
Affected:
- AWS mcp-gateway-registry: from 1.0.9, through 1.24.7
Fixed versions: 1.25.0.
Conditions (all must be true for the bug to be hit):
- Deployments running mcp-gateway-registry versions 1.0.9 through 1.24.7 (source: https://aws.amazon.com/security/security-bulletins/2026-179-aws/)
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
Attacker needs: network access, low-privilege login, no user action.
Workaround: Limit POST /api/servers/groups/* and the other /api/servers/* mutation routes to trusted administrator identities at the ingress or proxy layer, or block them for non-admin callers. (source: https://aws.amazon.com/security/security-bulletins/2026-179-aws/)
CISA KEV: CVE-2026-100307 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-100307 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://aws.amazon.com/security/security-bulletins/2026-179-aws/
- https://github.com/agentic-community/mcp-gateway-registry/releases/tag/1.25.0
- https://github.com/agentic-community/mcp-gateway-registry/security/advisories/GHSA-rxf3-qgpv-wxvr
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-100307
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-100307"}.Timeline
- CVE published
- First seen by cve.now
Affected versions
- AWS mcp-gateway-registry
From 1.0.9 · through 1.24.7
Evidence 5
Vendor advisory · 2
Establishes: Affected and fixed versions.
- Advisory
- Advisory
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Other links · 1
- Patch
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-100307
Is CVE-2026-100307 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
The external management API does not check authorization properly, so an authenticated user with low privileges can escalate to registry administrator. That grants full administrative control over every registered gateway asset.Source: aws.amazon.com
Which versions are affected by CVE-2026-100307?
mcp-gateway-registry: from 1.0.9 through 1.24.7.Source: cve.now feed data
Am I affected, and how do I check?
Deployments running mcp-gateway-registry versions 1.0.9 through 1.24.7 are in the affected range. Compare the installed mcp-gateway-registry version against that range.Source: aws.amazon.com
How do I fix CVE-2026-100307?
Upgrade to mcp-gateway-registry 1.25.0, released 2026-06-27, which addresses this issue. If you cannot upgrade yet, limit POST /api/servers/groups/* and the other /api/servers/* mutation routes to trusted administrator identities at the ingress or proxy layer, or block them for non-admin callers.Source: aws.amazon.com