CVE-2026-42209

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Source
https://cve.org/CVERecord?id=CVE-2026-42209
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42209.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-42209
Aliases
  • GHSA-2789-vfcg-5922
Published
2026-05-08T21:40:43.284Z
Modified
2026-08-12T16:24:18.433007Z
Severity
  • 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
FlashMQ: Division by zero crash when using non-default deferred retained message setting
Details

FlashMQ is a MQTT broker/server, designed for multi-CPU environments. Prior to version 1.26.1, a remote client with retained publish permission can crash the FlashMQ broker when both setretainedmessagedefertimeout and setretainedmessagedefertimeout_spread are configured to non-default values, resulting in denial of service. If anonymous retained publishing is allowed, no authentication is required; otherwise, the attacker needs the corresponding publish permission. This issue has been patched in version 1.26.1.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42209.json",
    "cwe_ids": [
        "CWE-369"
    ]
}
References

Affected packages

Git / github.com/halfgaar/flashmq

Affected ranges

Type
GIT
Repo
https://github.com/halfgaar/flashmq
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
193b6e7767889511cfa8e933908ea5e6a1077a1f
Fixed
a326649e16eee1fa6ff74c87b103eb8eb601b5cf
Database specific
Show details 
{
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "1.26.1"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "REFERENCES"
    ]
}

Affected versions

v0.*
v0.10.0
v0.10.1
v0.11.0
v0.11.1
v0.11.2
v0.11.3
v0.11.4
v0.11.5
v0.11.6
v0.11.7
v0.11.8
v0.11.9
v0.12.0
v0.12.1
v0.13.0
v0.13.1
v0.5.0
v0.5.1
v0.5.2
v0.6.0
v0.6.1
v0.6.3
v0.7.0
v0.7.1
v0.8.0
v0.8.1
v0.9.0
v0.9.1
v0.9.2
v0.9.3
v0.9.4
v0.9.5
v0.9.6
v0.9.7
v0.9.8
v0.9.9
v1.*
v1.0.0
v1.0.1
v1.0.2
v1.1.0
v1.10.0
v1.11.0
v1.12.0
v1.12.1
v1.13.0
v1.13.1
v1.14.0
v1.15.0
v1.15.1
v1.15.2
v1.15.3
v1.15.4
v1.16.0
v1.17.0
v1.17.1
v1.17.2
v1.18.0
v1.18.1
v1.18.2
v1.19.0
v1.2.0
v1.2.1
v1.20.0
v1.21.0
v1.21.1
v1.22.0
v1.23.0
v1.24.0
v1.25.0
v1.26.0
v1.3.0
v1.3.1
v1.4.0
v1.4.1
v1.4.2
v1.4.3
v1.4.4
v1.4.5
v1.5.0
v1.6.0
v1.6.1
v1.6.2
v1.6.3
v1.6.4
v1.6.5
v1.6.6
v1.6.7
v1.6.8
v1.6.9
v1.7.0
v1.7.1
v1.7.10
v1.7.11
v1.7.2
v1.7.3
v1.7.4
v1.7.5
v1.7.6
v1.7.7
v1.7.8
v1.7.9
v1.8.0
v1.8.1
v1.8.2
v1.8.3
v1.8.4
v1.9.0
v1.9.1

Database specific

vanir_signatures_modified 
"2026-08-12T16:24:18Z"
source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42209.json"
vanir_signatures 
[
    {
        "target": {
            "file": "subscriptionstore.cpp"
        },
        "id": "CVE-2026-42209-e6337151",
        "signature_type": "Line",
        "source": "https://github.com/halfgaar/flashmq/commit/193b6e7767889511cfa8e933908ea5e6a1077a1f",
        "signature_version": "v1",
        "deprecated": false,
        "digest": {
            "threshold": 0.9,
            "line_hashes": [
                "138165048839958869210583791425133712750",
                "22018605384051317281846779510216209006",
                "50972820445124572842254708106828772164",
                "308506853646627152287636873492342340212",
                "52595365389558395055774363130953779106"
            ]
        }
    }
]