CVE-2026-2966Public exploitNetwork attack vector

DNS spoofing via constant transaction identifiers

Published Feb 23, 2026 · Updated Feb 23, 2026

DNS transaction ID weakness in Cesanta Mongoose 7.0 through 7.20 allows remote attackers to redirect hostname resolution. In mg_sendnsreq, an empty active-request list resets the identifier to 1, while dns_cb removes each completed request and recreates that condition. An attacker must win the UDP response race and spoof the DNS source; an accepted reply makes the application connect to an attacker-chosen address.

CVSS severity3.7
Low
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

DNS transaction ID weakness in Cesanta Mongoose 7.0 through 7.20 allows remote attackers to redirect hostname resolution. In mg_sendnsreq, an empty active-request list resets the identifier to 1, while dns_cb removes each completed request and recreates that condition. An attacker must win the UDP response race and spoof the DNS source; an accepted reply makes the application connect to an attacker-chosen address.

The record

CVE
CVE-2026-2966
Published
Feb 23, 2026
Updated
Feb 23, 2026
Vendor
Cesanta
Product
Mongoose
Classifications
CWE-330, CWE-310, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=7.0
  2. Affected versionversion=7.1
  3. Affected versionversion=7.10
  4. Affected versionversion=7.11
  5. Affected versionversion=7.12
  6. Affected versionversion=7.13
  7. Affected versionversion=7.14
  8. Affected versionversion=7.15
  9. Affected versionversion=7.16
  10. Affected versionversion=7.17
  11. Affected versionversion=7.18
  12. Affected versionversion=7.19
  13. Affected versionversion=7.2
  14. Affected versionversion=7.20
  15. Affected versionversion=7.3
  16. Affected versionversion=7.4
  17. Affected versionversion=7.5
  18. Affected versionversion=7.6
  19. Affected versionversion=7.7
  20. Affected versionversion=7.8
  21. Affected versionversion=7.9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Cesanta · Mongooseversion=7.0; version=7.1; version=7.10; version=7.11; version=7.12; version=7.13; version=7.14; version=7.15; version=7.16; version=7.17; version=7.18; version=7.19; version=7.2; version=7.20; version=7.3; version=7.4; version=7.5; version=7.6; version=7.7; version=7.8; version=7.9

Published CVSS scores

2.9VulDBCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P
3.7VulDBCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
2.6VulDBAV:N/AC:H/Au:N/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-330Use of Insufficiently Random Values
CWE-310Cryptographic Issues
T1557Adversary-in-the-Middle

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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