# CVE-2026-86452: MISP Unauthenticated Mail Endpoints Allow Unbounded Storage Consumption and Request Flooding

> Unauthenticated attackers can cause denial of service by flooding MISP with unbounded password reset requests, consuming storage and resources.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Sep 2026
- **Updated:** 14 Sep 2026
- **Also known as:** GHSA-6crc-w8rh-cr5w

## What is CVE-2026-86452?

CVE-2026-86452 is a high-severity denial of service vulnerability in Misp-Project Misp, published on 7 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Affected versions of MISP permit unauthenticated or weakly constrained request paths to perform persistent work without adequate input bounds or rate limiting.

The users/forgot password-reset endpoint accepted an attacker-controlled email value without first imposing a reasonable length bound or validating its format. That value was then used to create an audit log entry and queue a password-reset job, causing the supplied value to be persisted more than once per request. The commit explicitly states that an unbounded unauthenticated request field was stored twice per call with no throttle.

The fix adds:

 - a maximum email input length of 1024 bytes;
 - email-format validation before persistent work;
 - a per-source pre-authentication request budget;
 - HTTP 429 responses when that budget is exceeded;
 - a 15-minute cooldown for API-access request emails;
 - POST-only handling and CSRF protection for the API-access request endpoint.

The new flood filter is specifically intended to limit persistent storage costs from anonymous requests such as password resets, registrations, and failed REST authentication attempts.

Version affected: ≤2.5.45

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-86452?

It affects 1 product.


Products: Misp-Project Misp.

## How do I fix CVE-2026-86452?

No fix has been published for CVE-2026-86452 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-86452 being exploited?

There is no known exploitation of CVE-2026-86452 in the wild and no public exploit code.

## Other vulnerabilities in Misp-Project Misp

- [CVE-2024-46918](https://insights.sbomify.com/CVE-2024-46918/): Missing authorization in n/a (critical 9.8)
- [CVE-2024-45509](https://insights.sbomify.com/CVE-2024-45509/): Missing authorization in n/a (critical 9.8)
- [CVE-2024-29858](https://insights.sbomify.com/CVE-2024-29858/): File upload in n/a (critical 9.8)
- [CVE-2024-29859](https://insights.sbomify.com/CVE-2024-29859/): File upload in n/a (critical 9.8)
- [CVE-2024-25674](https://insights.sbomify.com/CVE-2024-25674/): File upload in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-86452 and fix it if it is affected.

What it is: CVE-2026-86452 is a high-severity denial of service vulnerability in Misp-Project Misp, published on 7 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-86452 in the wild and no public exploit code.

Affected product: Misp-Project Misp. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-86452/ (Markdown: https://insights.sbomify.com/CVE-2026-86452/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-86452
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-86452
- OSV: https://osv.dev/vulnerability/CVE-2026-86452

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-86452/
Summaries are generated and may contain mistakes; the official description above is the record.