Totolink TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327 PPPoE formIpv6Setup pppoe_dns2 buffer overflow

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$0-$5k0.40

Summaryinfo

A vulnerability categorized as very critical has been discovered in Totolink TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327. The impacted element is the function formIpv6Setup of the component PPPoE. The manipulation of the argument pppoe_dns2 results in buffer overflow. This vulnerability was named CVE-2026-42020. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability was found in Totolink TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327. It has been classified as very critical. Affected is the function formIpv6Setup of the component PPPoE. The manipulation of the argument pppoe_dns2 with an unknown input leads to a buffer overflow vulnerability. CWE is classifying the issue as CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at talosintelligence.com. This vulnerability is traded as CVE-2026-42020 since 04/23/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 10/21/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.5
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.9
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 9.1
CNA Vector (talos): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Buffer overflow
CWE: CWE-120 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

04/23/2026 CVE reserved
10/21/2026 +181 days Advisory disclosed
10/21/2026 +0 days VulDB entry created
10/21/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: talosintelligence.com
Status: Not defined

CVE: CVE-2026-42020 (🔒)
GCVE (CVE): GCVE-0-2026-42020
GCVE (VulDB): GCVE-100-424068

Entryinfo

Created: 10/21/2026 05:27
Changes: 10/21/2026 05:27 (62)
Complete: 🔍
Cache ID: 216::103

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