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TI-2026-55159 Aliases CVE-2026-79661GHSA-7xcp-744q-324g

Ech0 before 4.7.3 Unauthenticated fav_count Modification

Priority HIGH 70CWE-770Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · Low · Low
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-770.

Summary

Ech0 through 4.5.6 registers the PUT /api/echo/like/:id endpoint on the public router group without authentication or rate limiting. Unauthenticated attackers can increment the fav_count counter of any echo (including private echoes) by supplying its UUID, which can be harvested from the public GET /api/echo/page feed. Repeated requests are accepted without deduplication, each triggering a database write and a four-key cache invalidation, allowing attackers to inflate popularity metrics and amplify load on the database and cache. Fixed in 4.7.3.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.0043 37th percentileScored 2026-11-07
Fix Fixed Ech0 (lin-snow): 4.7.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
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-2026-55158 Ech0 before 4.7.3 Email Disclosure via Public APIPriority HIGH 70
    Show all 7 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-79661
  2. 2026-10-03 Alias added: GHSA-7xcp-744q-324g

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-2026-55158 Ech0 before 4.7.3 Email Disclosure via Public API 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