CVE-2026-35037
HighPublic exploitEch0: Unauthenticated SSRF in GetWebsiteTitle allows access to internal services and cloud metadata
Published Apr 3, 2026 · Updated Aug 12, 2026 · Also known as GHSA-cqgf-f4x7-g6wc, GO-2026-5331
Key Facts
Patch immediately- CVE-2026-35037 is a high-severity vulnerability (CVSS 7.2 v3.1) affecting Ech0, github.com/lin-snow/ech0 (go).
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 0.7% probability of exploitation in the next 30 days.
- Fixed versions are available, including Ech0 4.2.8, github.com/lin-snow/ech0 1.4.8-0.20260401031029-4ca56fea5ba4.
- Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
CVSS v3.1
7.2
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
EPSS (30-day exploit likelihood)
0.7%
Higher than 52.9% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2026-35037 brief as a PDF
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Description
Ech0 is an open-source, self-hosted publishing platform for personal idea sharing. Prior to 4.2.8, the GET /api/website/title endpoint accepts an arbitrary URL via the website_url query parameter and makes a server-side HTTP request to it without any validation of the target host or IP address. The endpoint requires no authentication. An attacker can use this to reach internal network services, cloud metadata endpoints (169.254.169.254), and localhost-bound services, with partial response data exfiltrated via the HTML tag extraction This vulnerability is fixed in 4.2.8.
Affected Products
3 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Ech0Ech0 | >= < 4.2.8 | 4.2.8 |
| github.com/lin-snow/ech0go | See advisory | 1.4.8-0.20260401031029-4ca56fea5ba4 |
Patched Releases
Ech0
4.2.8
github.com/lin-snow/ech0
1.4.8-0.20260401031029-4ca56fea5ba4
Timeline
Publicly disclosed
Apr 3, 2026
Last updated
Aug 12, 2026
Weakness Type
- CWE-918 Server-Side Request Forgery (SSRF)
References
FAQ
Common Questions.
Ech0 is an open-source, self-hosted publishing platform for personal idea sharing.
Affected: Ech0 versions >= < 4.2.8; github.com/lin-snow/ech0 (go). The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including Ech0 4.2.8, github.com/lin-snow/ech0 1.4.8-0.20260401031029-4ca56fea5ba4.
Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
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