CVE-2026-5245Public exploitNetwork attack vector

Unauthenticated code execution via mDNS stack overflow

Published Apr 2, 2026 · Updated Apr 2, 2026

Stack buffer overflow in Cesanta Mongoose 7.0 through 7.20 allows remote attackers to execute code via a crafted mDNS query. handle_mdns_record appends PTR, SRV, TXT, and A records to a 282-byte stack buffer without checking their combined length. The target must expose mDNS with oversized registered service metadata; on MIPS systems with executable stacks, one unauthenticated UDP query overwrites saved registers and the return address.

CVSS severity8.1
High
EPSS probability0.72%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack buffer overflow in Cesanta Mongoose 7.0 through 7.20 allows remote attackers to execute code via a crafted mDNS query. handle_mdns_record appends PTR, SRV, TXT, and A records to a 282-byte stack buffer without checking their combined length. The target must expose mDNS with oversized registered service metadata; on MIPS systems with executable stacks, one unauthenticated UDP query overwrites saved registers and the return address.

The record

CVE
CVE-2026-5245
Published
Apr 2, 2026
Updated
Apr 2, 2026
Vendor
Cesanta
Product
Mongoose
Classifications
CWE-121, CWE-119, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

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

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

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

5.6VulDBCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
5.1VulDBAV:N/AC:H/Au:N/C:P/I:P/A:P
8.1NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
2.9VulDBCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P

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-121Stack-based Buffer Overflow
CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
T1190Exploit Public-Facing Application

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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