CVE-2026-74858Public exploitNetwork attack vector

SSRF via protocol-only URL validation

Published Aug 17, 2026 · Updated Aug 18, 2026

Server-side request forgery in URL validation in jae-jae Fetcher MCP 0.3.9 and earlier allows attackers to read internal web content via crafted URLs. The fetch_url and fetch_urls tools only verify that the scheme is http or https, then pass the supplied URL to Playwright page.goto and return the fetched body without blocking loopback, private, link-local, reserved, or cloud metadata addresses or revalidating redirects. Reachability requires the ability to invoke those MCP tools, and exposed HTTP or SSE deployments can disclose internal services and instance metadata rather than directly execute code.

CVSS severity5.3
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Server-side request forgery in URL validation in jae-jae Fetcher MCP 0.3.9 and earlier allows attackers to read internal web content via crafted URLs. The fetch_url and fetch_urls tools only verify that the scheme is http or https, then pass the supplied URL to Playwright page.goto and return the fetched body without blocking loopback, private, link-local, reserved, or cloud metadata addresses or revalidating redirects. Reachability requires the ability to invoke those MCP tools, and exposed HTTP or SSE deployments can disclose internal services and instance metadata rather than directly execute code.

The record

CVE
CVE-2026-74858
Published
Aug 17, 2026
Updated
Aug 18, 2026
Vendor
jae-jae
Product
Fetcher MCP
Classifications
CWE-918, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.3.0
  2. Affected versionversion=0.3.1
  3. Affected versionversion=0.3.2
  4. Affected versionversion=0.3.3
  5. Affected versionversion=0.3.4
  6. Affected versionversion=0.3.5
  7. Affected versionversion=0.3.6
  8. Affected versionversion=0.3.7
  9. Affected versionversion=0.3.8
  10. Affected versionversion=0.3.9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

jae-jae · Fetcher MCPversion=0.3.0; version=0.3.1; version=0.3.2; version=0.3.3; version=0.3.4; version=0.3.5; version=0.3.6; version=0.3.7; version=0.3.8; version=0.3.9

Published CVSS scores

6.3VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
5.3VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
6.5VulDBAV:N/AC:L/Au:S/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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