CVE-2026-9137Network attack vector

Log flooding via one-megabyte truncation limit

Published May 20, 2026 · Updated May 20, 2026

Uncontrolled resource consumption in MISP 2.5.0 through 2.5.37 allows remote attackers to flood logs through CSP reports. The cspReport action in ServersController.php truncates the JSON-encoded csp-report field only after 1 MB, despite its intended 1 KB ceiling, and then logs it. Exposure requires the endpoint to accept requests from untrusted clients; repeated oversized reports consume log storage and processing resources without disclosing or altering application data.

CVSS severity5.1
Medium
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled resource consumption in MISP 2.5.0 through 2.5.37 allows remote attackers to flood logs through CSP reports. The cspReport action in ServersController.php truncates the JSON-encoded csp-report field only after 1 MB, despite its intended 1 KB ceiling, and then logs it. Exposure requires the endpoint to accept requests from untrusted clients; repeated oversized reports consume log storage and processing resources without disclosing or altering application data.

The record

CVE
CVE-2026-9137
Published
May 20, 2026
Updated
May 20, 2026
Vendor
MISP Project
Product
MISP
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 20, 2026CVE publishedPublication date reported by the CVE source.
  2. May 20, 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=2.5.0 <=2.5.37

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

MISP Project · MISPversion=2.5.0 <=2.5.37

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.1CIRCLCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA: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.

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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 exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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