Skip to content
Fencer Intel
medium 5.5

CVE-2026-79671 json

Ech0 before 4.4.3 SSRF via DNS Resolution Bypass

published 7mo ago modified 2mo ago also EUVD-2026-65443 , GHSA-r2x7-427f-rq69 , GO-2026-5603

cvss
5.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 24%
public exploits
0
none known

Summary

Ech0 before 4.4.3 contains a server-side request forgery vulnerability in the validateWebhookURL function (webhook_setting_service.go), which only validates literal IP addresses via net.ParseIP() and fails to reject hostnames that DNS-resolve to private or internal IPs (e.g., 169.254.169.254.nip.io). An attacker with admin privileges can create a webhook with such a hostname to bypass validation and cause the server to make requests to internal services, cloud metadata endpoints, and private network resources. The issue is fixed in 4.4.3.

Patch / fix

  • go github.com/lin-snow/ech0 4.4.3
  • lin-snow Ech0 4.4.3

Is CVE-2026-79671 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
2mo ago

Exploit prediction

0.31% chance of exploitation in the next 30 days, higher than 24% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/lin-snow/Ech0/security/advisories/GHSA-r2x7-427f-rq69 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 5.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
CNA 3.1 5.5 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N
GitHub 3.1 5.5 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N
CNA 4.0 5.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
go github.com/lin-snow/ech0
<4.4.3
all versions
4.4.3

Affected products

  • lin-snow Ech0

Classification

Weakness
  • CWE-918 Server-Side Request Forgery

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.