A security vulnerability has been detected in Cesanta Mongoose up to 7.20. This affects the function getpeer of the file /src/net_builtin.c of the component TCP Sequence Number Handler. The manipulation leads to improper verification of source of a communication channel. The attack may be initiated remotely. The attack's complexity is rated as high. The exploitability is reported as difficult. The exploit has been disclosed publicly and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Metrics

Attack Vector Network

Attack Complexity High

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact Low

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact Low

User Interaction None

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact Low

User Interaction None

Access Vector Network

Access Complexity High

Authentication None

Confidentiality Impact None

Integrity Impact None

Availability Impact Partial

This CVE is not in the KEV list.

Exploitation poc

Automatable no

Technical Impact partial

Affected Vendors & Products

Vendors Products
Cesanta
  • Mongoose

Configuration 1 [-]

cpe:2.3:a:cesanta:mongoose:*:*:*:*:*:*:*:*

No data.

References
Link Providers
https://www.spirityenterprise.com/pentest spirity
https://www.spirityenterprise.com/managed-detection-response spirity
https://github.com/dwBruijn/CVEs/blob/main/Mongoose/tcp_rst.md cve-icon cve-icon
https://github.com/dwBruijn/CVEs/blob/main/Mongoose/tcp_rst.md#poc cve-icon cve-icon
https://vuldb.com/?ctiid.347334 cve-icon cve-icon
https://vuldb.com/?id.347334 cve-icon cve-icon
https://vuldb.com/?submit.755450 cve-icon cve-icon
History

Mon, 23 Feb 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Mon, 23 Feb 2026 03:30:00 +0000

Type Values Removed Values Added
Description A security vulnerability has been detected in Cesanta Mongoose up to 7.20. This affects the function getpeer of the file /src/net_builtin.c of the component TCP Sequence Number Handler. The manipulation leads to improper verification of source of a communication channel. The attack may be initiated remotely. The attack's complexity is rated as high. The exploitability is reported as difficult. The exploit has been disclosed publicly and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Title Cesanta Mongoose TCP Sequence Number net_builtin.c getpeer verification of source
First Time appeared Cesanta
Cesanta mongoose
Weaknesses CWE-940
CPEs cpe:2.3:a:cesanta:mongoose:*:*:*:*:*:*:*:*
Vendors & Products Cesanta
Cesanta mongoose
References
Metrics cvssV2_0

{'score': 2.6, 'vector': 'AV:N/AC:H/Au:N/C:N/I:N/A:P/E:POC/RL:ND/RC:UR'}

cvssV3_0

{'score': 3.7, 'vector': 'CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R'}

cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R'}

cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P'}
cve-icon MITRE

Status: PUBLISHED

Assigner: VulDB

Published:

Updated: 2026-02-23T13:32:57.830Z

Reserved: 2026-02-22T07:57:28.584Z

Link: CVE-2026-2967

cve-icon Vulnrichment

Updated: 2026-02-23T13:32:51.789Z

cve-icon NVD

Status : Analyzed

Published: 2026-02-23T04:16:02.040

Modified: 2026-02-23T20:17:44.177

Link: CVE-2026-2967

cve-icon Redhat

No data.