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TI-2026-77037 Aliases CVE-2026-42020GHSA-vcwc-rc3q-4m7r

Stack buffer overflows in Totolink X2000R IPv6 PPPoE setup handler

Priority MEDIUM 43CWE-121Published · Updated

Key facts

Attack vector
Network
Privileges required
High
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-121 and the CVSS impact.

Summary

Multiple stack-based buffer overflows exist in the boa formIpv6Setup pppoe functionality of Totolink X2000R TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327. A specially crafted HTTP request that sets the pppoe_dns2 parameter overflows a stack buffer (CWE-121), which can lead to arbitrary code execution. An authenticated remote attacker can send such a request to trigger the flaw.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

Multiple stack-based buffer overflow vulnerabilities exist in the boa formIpv6Setup pppoe functionality of Totolink X2000R TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327. A specially crafted HTTP request can lead to arbitrary code execution. An attacker can make an authenticated HTTP request to trigger these vulnerabilities. This vulnerability concerns the pppoe_dns2 parameter.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00737 54th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

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

Affected products

VendorProductAffected versionsFixed inStatusSource
TOTOLINKTotolinkTOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327—No fix listedCNA
  • Totolink VendorTOTOLINK Affected TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327 Fixed in — No fix listed CNA

Remediation

The sources list no fixed version for Totolink X2000R.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Timeline

  1. 2026-10-21 Threatist record created from CVE-2026-42020
  2. 2026-10-21 Alias added: GHSA-vcwc-rc3q-4m7r
  3. 2026-10-28 CISA SSVC decision points changed

References

Other 1

  • TI-2023-25090 An issue in TOTOLINK A3700R v.9.1.2u.6165_20211012 allows a remote attacker to execute… CVSS 3.1CRITICAL 9.8
  • TI-2026-80926 TOTOLINK A950RG stack-based overflow in infostat.cgi via CONTENT_LENGTH CVSS 4.0CRITICAL 10.0
  • TI-2026-79142 Command injection in TOTOLINK A950RG UploadCustomModule function CVSS 4.0CRITICAL 10.0
  • TI-2026-79031 TOTOLINK EX200 setWiFiAclAddConfig stack-based buffer overflow CVSS 4.0CRITICAL 10.0
  • TI-2026-79012 Stack-based buffer overflow in TOTOLINK EX200 setStaticDhcpConfig CVSS 4.0CRITICAL 10.0
  • TI-2026-67719 Stack-based overflow in Totolink A3002MU QoS rule handler CVSS 4.0CRITICAL 10.0
See all 1321 →

Sources

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