Low severity · published Feb 23, 2026
CVE-2026-2967
Cesanta Mongoose TCP Sequence Number net_builtin.c getpeer verification of source
3.7
CVSS
0.6%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 47% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MO
Mongoose · Cesanta
7.0; 7.1; 7.2; 7.3; 7.4; 7.5; +15 more · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-2967
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-2967
Exploit
https://github.com/dwBruijn/CVEs/blob/main/Mongoose/tcp_rst.md
Exploit
https://github.com/dwBruijn/CVEs/blob/main/Mongoose/tcp_rst.md#poc
Permissions Required
https://vuldb.com/?ctiid.347334
Third Party Advisory
https://vuldb.com/?id.347334
Third Party Advisory
https://vuldb.com/?submit.755450
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