CVE
Server-side request forgery in the server registration and update API in mcp-gateway-registry
Affects mcp-gateway-registry versions 1.0.3 through 1.34.0, where authenticated users with permission to register or modify a server can exploit the flaw. No vendor rating is given, only CVSS 8.5 (High). Fixed in 1.35.0.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 1.35.0
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Impacted mcp-gateway-registry versions are v1.0.3 through 1.34.0. Attacker must be an authenticated user with permission to register or modify a server.
- 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
Server-side request forgery (SSRF) in the server registration and update API in Amazon mcp-gateway-registry before 1.35.0 might allow an authenticated remote user to send requests from the gateway to internal network services and cloud instance metadata endpoints and read the responses via a crafted request.
To remediate this issue, users should upgrade to version 1.35.0.
Who should check
Teams running mcp-gateway-registry from v1.0.3 through 1.34.0, especially where users can register or modify MCP servers. Check any deployment that lets accounts add server upstream addresses.
Not fixed by: Upgrading does not correct server upstream addresses stored before 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
- Severity8.5/10CVSS 8.5
- 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.
Impacted mcp-gateway-registry versions are v1.0.3 through 1.34.0. Attacker must be an authenticated user with permission to register or modify a server.Upgrade to a fixed version: 1.35.0.
Workaround: Limit the permission to register and modify servers to trusted accounts.
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-2026-125926 (Server-side request forgery in the server registration and update API in mcp-gateway-registry), 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-2026-125926 (entry last updated 2026-11-11):
Affected:
- AWS mcp-gateway-registry: from 1.0.3, through 1.34.0
Fixed versions: 1.35.0.
Conditions (all must be true for the bug to be hit):
- Impacted mcp-gateway-registry versions are v1.0.3 through 1.34.0. (source: https://aws.amazon.com/security/security-bulletins/2026-180-aws/)
- Attacker must be an authenticated user with permission to register or modify a server. (source: https://aws.amazon.com/security/security-bulletins/2026-180-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 the permission to register and modify servers to trusted accounts. (source: https://aws.amazon.com/security/security-bulletins/2026-180-aws/)
CISA KEV: CVE-2026-125926 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-125926 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/2026-180-aws/
- https://github.com/agentic-community/mcp-gateway-registry/releases/tag/1.35.0
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-2026-125926
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-2026-125926"}.Timeline
- CVE published
- First seen by cve.now
Affected versions
- AWS mcp-gateway-registry
From 1.0.3 · through 1.34.0
Evidence 4
Vendor advisory · 1
Establishes: Affected and fixed versions.
- 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-2026-125926
Is CVE-2026-125926 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 server registration and update API in mcp-gateway-registry has a server-side request forgery flaw. An authenticated user who is allowed to register or modify a server can use it to make the server send requests to destinations the user chooses.Source: aws.amazon.com
Which versions are affected by CVE-2026-125926?
mcp-gateway-registry: from 1.0.3 through 1.34.0.Source: cve.now feed data
Am I affected, and how do I check?
Versions 1.0.3 through 1.34.0 are affected. To check a deployment, look at the mcp-gateway-registry version it runs. The issue requires an authenticated account with permission to register or modify servers.Source: aws.amazon.com
How do I fix CVE-2026-125926?
Upgrade to mcp-gateway-registry 1.35.0, which the vendor says addresses this issue. Until the upgrade is applied, limit the permission to register and modify servers to trusted accounts.Source: aws.amazon.com