# CVE-2026-26747: Open redirect in n/a

> Attackers can poison password reset links via Host header injection, potentially leading to account takeover in Monica CRM.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Feb 2026
- **Updated:** 23 Feb 2026
- **Also known as:** GHSA-xf4f-qj26-72pf

## What is CVE-2026-26747?

CVE-2026-26747 is a critical vulnerability in n/a, published on 20 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A Host Header Poisoning vulnerability exists in Monica 4.1.2 due to improper handling of the HTTP Host header in app/Providers/AppServiceProvider.php, combined with the default misconfiguration where the "app.force_url" is not set and default is "false". The application generates absolute URLs (such as those used in password reset emails) using the user-supplied Host header. This allows remote attackers to poison the password reset link sent to a victim,

Weakness: CWE-644 (Improper Neutralization of HTTP Headers for Scripting Syntax)

## Which versions are affected by CVE-2026-26747?

It affects 1 product.


Products: Monicahq Monica.

## How do I fix CVE-2026-26747?

No fix has been published for CVE-2026-26747 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-26747 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-26747 exists.

## Other vulnerabilities in n/a

- [CVE-2024-54996](https://insights.sbomify.com/CVE-2024-54996/): Cross-site scripting in n/a (high 8.8)
- [CVE-2023-1031](https://insights.sbomify.com/CVE-2023-1031/): Cross-site scripting in MonicaHQ (high 8.8)
- [CVE-2023-1094](https://insights.sbomify.com/CVE-2023-1094/): Code injection in MonicaHQ (high 8.0)
- [CVE-2024-54999](https://insights.sbomify.com/CVE-2024-54999/): Code injection in n/a (medium 6.5)
- [CVE-2024-54994](https://insights.sbomify.com/CVE-2024-54994/): Cross-site scripting in n/a (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-26747 and fix it if it is affected.

What it is: CVE-2026-26747 is a critical vulnerability in n/a, published on 20 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-26747 exists.

Affected product: n/a. 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-2026-26747/ (Markdown: https://insights.sbomify.com/CVE-2026-26747/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-26747
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-26747
- OSV: https://osv.dev/vulnerability/CVE-2026-26747

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-26747/
Summaries are generated and may contain mistakes; the official description above is the record.