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Vulnerability · Published Feb 23, 2026 · Assigned by VulDB

CVE-2026-2966Cesanta Mongoose DNS Transaction ID dns.c mg_sendnsreq random values

Low 3.7

In plain English

A low-severity weak randomness in Mongoose from Cesanta. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)3.7Low
Exploit odds (30 days)0.4%top 61.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

A weakness has been identified in Cesanta Mongoose up to 7.20. The impacted element is the function mg_sendnsreq of the file /src/dns.c of the component DNS Transaction ID Handler. Executing a manipulation of the argument random can lead to insufficiently random values. The attack can be launched remotely. The attack requires a high level of complexity. The exploitability is regarded as difficult. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12swupdateno fix listedDEBIAN-CVE-2026-2966
Debian:13swupdateno fix listedDEBIAN-CVE-2026-2966
Debian:14swupdate2025.12+dfsg-10DEBIAN-CVE-2026-2966
Ubuntu:22.04:LTSopencpnno fix listedUBUNTU-CVE-2026-2966
Ubuntu:24.04:LTSopencpnno fix listedUBUNTU-CVE-2026-2966
Ubuntu:25.10opencpnno fix listedUBUNTU-CVE-2026-2966
Ubuntu:26.04:LTSopencpnno fix listedUBUNTU-CVE-2026-2966
Ubuntu:26.10opencpnno fix listedUBUNTU-CVE-2026-2966

Affected products (as reported)

VendorProductVersions
Cesanta Mongoose 7.07.17.27.37.47.57.67.7

Weakness: CWE-330, CWE-310 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:X/RC:R

References