5.1
MEDIUM CVSS 4.0
CVE-2026-9137
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.

INFO

Published Date :

May 20, 2026, 6:43 p.m.

Last Modified :

May 20, 2026, 6:43 p.m.

Remotely Exploit :

Yes !

Source :

CIRCL
Affected Products

The following products are affected by CVE-2026-9137 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 MEDIUM 5a6e4751-2f3f-4070-9419-94fb35b644e8
Solution
Enforce the intended 1 KB limit for CSP reports to prevent log flooding.
  • 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.

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).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-9137 vulnerability anywhere in the article.

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.