Generation of Predictable Numbers or Identifiers Affecting cesanta/mongoose package, versions [,7.21)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-UNMANAGED-CESANTAMONGOOSE-15325855
- published23 Feb 2026
- disclosed23 Feb 2026
- creditdwbruijn
Introduced: 23 Feb 2026
CVE-2026-2966 (opens in a new tab)How to fix?
Upgrade cesanta/mongoose to version 7.21 or higher.
Overview
cesanta/mongoose is a networking library for C/C++. It implements event-driven non-blocking APIs for TCP, UDP, HTTP, WebSocket, MQTT.
Affected versions of this package are vulnerable to Generation of Predictable Numbers or Identifiers via the mg_sendnsreq function. An attacker can predict DNS transaction IDs by analyzing insufficiently random values generated during DNS requests, potentially enabling DNS spoofing or cache poisoning attacks.