# CVE-2026-90893: MISP UserSettingsController CSRF Protection Bypass on setTheme, setHomePage, and eventIndexColumnToggle Endpoints

> Attackers can forge requests to modify MISP user settings, such as the homepage URL, potentially enabling phishing attacks against authenticated users.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 14 Sep 2026
- **Updated:** 14 Sep 2026
- **Also known as:** GHSA-g37r-568w-2pwm

## What is CVE-2026-90893?

CVE-2026-90893 is a medium-severity vulnerability in MISP, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

MISP contains a Cross-Site Request Forgery (CSRF) vulnerability in the UserSettingsController. The actions setTheme, setHomePage, and eventIndexColumnToggle were explicitly added to the Security component's unlockedActions list, which disabled all CSRF validation (both token and field-hash checks) for those endpoints. Because these endpoints accept POST requests and modify per-user application state (theme selection, default homepage URL, and event index column visibility), an attacker who can induce a logged-in MISP user to load a malicious page (e.g., via a crafted link, embedded image, or auto-submitting form) can forge requests that alter the victim's settings without their knowledge or consent. The most impactful action is setHomePage, which allows an attacker to redirect the victim's default landing page to an arbitrary attacker-controlled URL, potentially facilitating phishing or further social engineering. The setTheme action can alter the user's visual theme, and eventIndexColumnToggle can change which columns are displayed in the event index view. No authentication bypass is involved; the victim must already be authenticated to MISP. The vulnerability was reported by the Scottish Government National Cyber Team.

Version affected: ≤2.5.45

Weakness: CWE-352 (Cross-Site Request Forgery)

## Which versions are affected by CVE-2026-90893?


## How do I fix CVE-2026-90893?

No fix has been published for CVE-2026-90893 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-90893 being exploited?

There is no known exploitation of CVE-2026-90893 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90893 and fix it if it is affected.

What it is: CVE-2026-90893 is a medium-severity vulnerability in MISP, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-90893 in the wild and no public exploit code.

Affected product: 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-2026-90893/ (Markdown: https://insights.sbomify.com/CVE-2026-90893/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90893
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90893
- OSV: https://osv.dev/vulnerability/CVE-2026-90893

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90893/
Summaries are generated and may contain mistakes; the official description above is the record.