CVE-2026-35036Public exploitNetwork attack vector

Internal service access via unauthenticated URL fetch

Published Apr 6, 2026 · Updated Apr 6, 2026

Server-side request forgery in Ech0 before 4.2.8 allows remote attackers to access internal HTTP services through the website preview API. The unauthenticated /api/website/title route passes its website_url value to SendRequest without destination filtering, follows redirects, disables TLS verification, and reads the complete response. Network access to an Ech0 instance is sufficient to initiate requests from the server's network position; returned page titles can disclose reachable content, while full-body reads can exhaust memory.

CVSS severity7.5
High
EPSS probability0.33%
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 Ech0 before 4.2.8 allows remote attackers to access internal HTTP services through the website preview API. The unauthenticated /api/website/title route passes its website_url value to SendRequest without destination filtering, follows redirects, disables TLS verification, and reads the complete response. Network access to an Ech0 instance is sufficient to initiate requests from the server's network position; returned page titles can disclose reachable content, while full-body reads can exhaust memory.

The record

CVE
CVE-2026-35036
Published
Apr 6, 2026
Updated
Apr 6, 2026
Vendor
lin-snow
Product
Ech0
Classifications
CWE-918, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=< 4.2.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

lin-snow · Ech0version=< 4.2.8

Published CVSS scores

7.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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.

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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
Privilegesunauthenticated
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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