CVE-2026-9137
📛 CVE Title
CSP Report Endpoint Log Flooding via Incorrect Size Limit
Description
The CSP report endpoint intended to limit logged CSP reports to 1 KB but incorrectly allowed reports up to 1 MB before truncation. On deployments where the endpoint is reachable by untrusted clients, this could allow attackers to generate excessive log volume and contribute to resource exhaustion or log flooding.
Description (MITRE) cveawg.mitre.org
Pulled from cveawg.mitre.org/api/cve/CVE-2026-9137 on 2026-07-01. Shown when MITRE's text differs from the cvelistV5 mirror.
The CSP report endpoint in MISP intended to limit logged CSP reports to 1 KB but incorrectly allowed reports up to 1 MB before truncation. On deployments where the endpoint is reachable by untrusted clients, this could allow attackers to generate excessive log volume and contribute to resource exhaustion or log flooding.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- CIRCL
- CVSS severity
- MEDIUM
- CVSS score
- 5.1 / 10
- CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N- Effective score
- 5.1 / 10 MEDIUM source: CNA overview
- CWE(s)
-
CWE-400 - Reserved
- 2026-05-20
- Published
- 2026-05-20 18:43 UTC
- Last updated
- 2026-05-20 19:26 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/9xxx/CVE-2026-9137.json
- Linked Threat
- CVE-2026-9137 — CVE-2026-9137
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-05-20 20:16:46 UTC
- NVD last modified
- 2026-05-21 16:04:33 UTC
- EPSS score
- 0.0004 (probability of exploitation in next 30 days)
- EPSS percentile
- 12.99% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24
NVD / KEV / EPSS data refreshed 2026-05-25 00:32 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
European Union Vulnerability Database ENISA EUVD
ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.
- EUVD ID
-
EUVD-2026-31155 - Assigner
- CIRCL
- Published
- May 20, 2026, 6:43:30 PM
- Updated
- May 29, 2026, 6:57:50 AM
- EUVD base score (CVSS 4.0)
-
5.1 / 10
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - EUVD-reported EPSS
- 0.0600
- Vendors
- MISP
- Products
-
MISP (2.5.0 ≤2.5.37)
- Aliases
-
GHSA-gfvj-j222-m85v
ENISA description: The CSP report endpoint in MISP intended to limit logged CSP reports to 1 KB but incorrectly allowed reports up to 1 MB before truncation. On deployments where the endpoint is reachable by untrusted clients, this could allow attackers to generate excessive log volume and contribute to resource exhaustion or log flooding.
EUVD references (1)
Affected products (1)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| misp | misp |
2.5.0 (affected)
|
— |
Vendor references (1)
References embedded in the original CVE record by the assigning CNA.
Web references (4)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
- https://github.com/MISP/MISP/commit/02932cccab230b295afcaf5aa05e363d30db0ec9 tenable:github.com
- https://nvd.nist.gov/vuln/detail/CVE-2026-9137 tenable:nvd.nist.gov
- https://www.cve.org/CVERecord?id=CVE-2026-9137 tenable:www.cve.org
- https://www.first.org/epss/ tenable:www.first.org
NVD-tagged references (1)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- https://github.com/MISP/MISP/commit/02932cccab230b295afcaf5aa05e363d30db0ec9 5a6e4751-2f3f-4070-9419-94fb35b644e8
Remediations (18)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:app.opencve.io
The CSP report endpoint intended to limit logged CSP reports to 1 KB but incorrectly allowed reports up to 1 MB before truncation. On deployments where the endpoint is reachable by untrusted clients, this could allow attackers to generate excessive log volume and contribute to resource exhaustion or log flooding.
2026-05-23 22:18 UTC -
web:blog.talosintelligence.com
Microsoft has released its monthly security update for May 2026 , which includes 137 vulnerabilities affecting a range of products, including 16 that Microsoft marked as "critical".
2026-05-23 22:18 UTC -
web:krebsonsecurity.com
Microsoft expects that exploitation is more likely. May's Patch Tuesday is a welcome respite from April, which saw Microsoft fix a near-record 167 security flaws.
2026-05-23 22:18 UTC -
web:nvd.nist.gov
Description The CSP report endpoint intended to limit logged CSP reports to 1 KB but incorrectly allowed reports up to 1 MB before truncation. On deployments where the endpoint is reachable by untrusted clients, this could allow attackers to generate excessive log volume and contribute to resource exhaustion or log flooding.
2026-05-23 22:18 UTC -
web:portal.msrc.microsoft.com
The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.
2026-05-23 22:18 UTC -
web:vulmon.com
Vulnerability Summary The CSP report endpoint intended to limit logged CSP reports to 1 KB but incorrectly allowed reports up to 1 MB before truncation. On deployments where the endpoint is reachable by untrusted clients, this could allow malicious users to generate excessive log volume and contribute to resource exhaustion or log flooding. Subscribe to Misp
2026-05-23 22:18 UTC -
web:www.cisa.gov
Updated October 29, 2025: CISA has updated this Alert to include revised information on vulnerable product identification, potential threat activity detections, and additional resources. Microsoft released an update to address a critical remote code execution vulnerability impacting Windows Server Update Service (WSUS) in Windows Server (2012, 2016, 2019, 2022, and 2025), CVE -2025-59287
2026-05-23 22:18 UTC -
web:www.dbtsupport.com
The May 2026 Microsoft Patch Tuesday release includes security updates across supported Microsoft products and should be reviewed directly in the Microsoft Security Update Guide for the final CVE list, affected products, severity ratings, exploitability assessments, and any revised guidance.
2026-05-23 22:18 UTC -
web:www.thehackerwire.com
On deployments... How do I fix or mitigate CVE-2026-9137 ? To protect against CVE-2026-9137 , you should: (1) Apply the latest security patches from the vendor, (2) Check official security advisories for specific remediation steps, (3) Update affected software to the latest version, and (4) Monitor your systems for any signs of exploitation.
2026-05-23 22:18 UTC -
web:www.zdnet.com
Install Microsoft's emergency Windows patch now - what it fixes and why it was rushed out Microsoft issued an out-of-band fix after its latest update introduced a nasty surprise.
2026-05-23 22:18 UTC -
web:access.redhat.com
Learn about our open source products, services, and company. You are here
2026-06-03 22:32 UTC -
web:access.redhat.com
Learn about our open source products, services, and company. You are here
2026-06-03 22:32 UTC -
web:blog.qualys.com
May 2026's Patch Tuesday arrives with Microsoft addressing a fresh set of vulnerabilities across its ecosystem, reinforcing the ongoing need for timely patching in an increasingly threat-heavy…
2026-06-03 22:32 UTC -
web:mondoo.com
CVE-2026-9137 - HIGH severity: CSP Report Endpoint Log Flooding in MISP via Incorrect Size Limit
2026-06-03 22:32 UTC -
web:petri.com
If a Group Policy setting is available to roll back a fix , it is included in the Windows Update KB article and release notes as a mitigation for a known issue.
2026-06-03 22:32 UTC -
web:support.microsoft.com
This update for Windows 11, version 25H2 and 24H2 (KB5084597) incudes security improvements. To learn more about differences between security updates, optional non-security preview updates, out-of-band (OOB) updates, and continuous innovation, see Windows monthly updates explained. For information on Windows update terminology, see the different types of Windows software updates. To view the ...
2026-06-03 22:32 UTC -
web:www.lansweeper.com
Which vulnerabilities, issues, and other things did Microsoft update? Discover what's new using Lansweeper's Patch Tuesday May 2026 summary.
2026-06-03 22:32 UTC -
web:zecurit.com
Get the complete breakdown of Microsoft's June 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .
2026-06-03 22:32 UTC
AI Forensic Analysis
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-9137.json.
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