CVE-2026-9137
CSP Report Endpoint Log Flooding in MISP via Incorrect Size Limit
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.
INFO
Published Date :
May 20, 2026, 8:16 p.m.
Last Modified :
June 2, 2026, 4:34 p.m.
Remotely Exploit :
Yes !
Source :
5a6e4751-2f3f-4070-9419-94fb35b644e8
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | MEDIUM | 5a6e4751-2f3f-4070-9419-94fb35b644e8 | ||||
| CVSS 4.0 | MEDIUM | 5a6e4751-2f3f-4070-9419-94fb35b644e8 |
Solution
- Implement strict size enforcement for CSP report logs.
- Truncate logs exceeding the 1 KB limit.
- Restrict access to the CSP report endpoint.
- Monitor log volume for anomalies.
Public PoC/Exploit Available at Github
CVE-2026-9137 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-9137.
| URL | Resource |
|---|---|
| https://github.com/MISP/MISP/commit/02932cccab230b295afcaf5aa05e363d30db0ec9 | Patch |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-9137 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-9137
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-9137 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-9137 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jun. 02, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CPE Configuration OR *cpe:2.3:a:misp:misp:*:*:*:*:*:*:*:* versions from (including) 2.5.0 up to (excluding) 2.5.38 Added Reference Type CIRCL: https://github.com/MISP/MISP/commit/02932cccab230b295afcaf5aa05e363d30db0ec9 Types: Patch -
CVE Modified by 5a6e4751-2f3f-4070-9419-94fb35b644e8
May. 29, 2026
Action Type Old Value New Value Changed 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. 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. -
New CVE Received by 5a6e4751-2f3f-4070-9419-94fb35b644e8
May. 20, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-400 Added Reference https://github.com/MISP/MISP/commit/02932cccab230b295afcaf5aa05e363d30db0ec9