Read the docs
TI-2026-55161 Aliases CVE-2026-79663GHSA-9277-65xq-8gww

Ech0 before 4.7.3 Stored XSS via RSS feed tag names

Priority LOW 22CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
High
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Cross-site scripting
Confidentiality · integrity · availability
Low · Low · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-79.

Summary

Ech0 before 4.7.3 contains a stored cross-site scripting vulnerability in the public RSS feed where tag names and markdown content are rendered without HTML escaping. Attackers with admin privileges can inject malicious tag names or raw HTML in echo content that executes as JavaScript in RSS readers that render HTML-type summaries, affecting anonymous subscribers and other users.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00251 16th percentileScored 2026-11-07
Fix Fixed Ech0 (lin-snow): 4.7.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
lin-snowEch0before 4.7.34.7.3Patch availableCNA
  • Ech0 Vendorlin-snow Affected before 4.7.3 Fixed in 4.7.3 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:ech0:ech0:*:*:*:*:*:*:*:*——lin-snow
  • cpe:2.3:a:ech0:ech0:*:*:*:*:*:*:*:* Versions — — ·lin-snow

Remediation

  • Fix · CNA Ech0 (lin-snow) Fixed in 4.7.3

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    lin-snow Ech0 4.7.3

    7 records Highest priority Priority HIGH 5 HIGH, 2 LOW

    Other records, highest priority first

    • TI-2026-55162 Ech0 before 4.7.3 Access Token Revocation BypassPriority HIGH 74
    • TI-2026-55160 Ech0 before 4.7.3 OAuth Redirect URI Validation BypassPriority HIGH 73
    • TI-2026-55159 Ech0 before 4.7.3 Unauthenticated fav_count ModificationPriority HIGH 70
    Show all 7 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-79663
  2. 2026-10-03 Alias added: GHSA-9277-65xq-8gww

References

Advisory 1

  • TI-2026-55162 Ech0 before 4.7.3 Access Token Revocation Bypass CVSS 4.0CRITICAL 9.1
  • TI-2026-55163 Ech0 before 4.5.1 Authorization Bypass via Session Tokens CVSS 4.0HIGH 8.7
  • TI-2026-55160 Ech0 before 4.7.3 OAuth Redirect URI Validation Bypass CVSS 4.0HIGH 8.8
  • TI-2026-27239 Ech0 Affected by Unauthenticated Server-Side Request Forgery in Website Preview Feature CVSS 3.1HIGH 7.5
  • TI-2026-27240 Ech0 affected by unauthenticated SSRF in GetWebsiteTitle allows access to internal services and cloud metadata CVSS 3.1HIGH 7.2
  • TI-2026-55159 Ech0 before 4.7.3 Unauthenticated fav_count Modification CVSS 4.0MEDIUM 6.9
See all 19 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences