# CVE-2026-24423: SmarterTools SmarterMail Missing Authentication for Critical Function

> Unauthenticated attackers can execute arbitrary OS commands on SmarterMail servers by directing the ConnectToHub API to a malicious HTTP server.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Yes, since 5 Feb 2026 (CISA KEV), used in ransomware
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 23 Jan 2026
- **Updated:** 4 Aug 2026
- **Also known as:** GHSA-7jpw-fm5p-f98m

## What is CVE-2026-24423?

CVE-2026-24423 is a critical command injection vulnerability in SmarterTools SmarterMail, published on 23 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

SmarterTools SmarterMail versions prior to build 9511 contain an unauthenticated remote code execution vulnerability in the ConnectToHub API method. The attacker could point the SmarterMail to the malicious HTTP server, which serves the malicious OS command. This command will be executed by the vulnerable application.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2026-24423?

It affects 1 product.


Products: Smartertools Smartermail.

## How do I fix CVE-2026-24423?

No fix has been published for CVE-2026-24423 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 26 Feb 2026.

## Is CVE-2026-24423 being exploited?

Yes. Attackers have exploited CVE-2026-24423 in the wild since at least 5 Feb 2026, including in ransomware campaigns.

Public exploit code:

- CVE-2026-24423 exp (github_poc): https://github.com/aavamin/CVE-2026-24423
- Unauthenticated RCE PoC for CVE-2026-24423 in SmarterTools SmarterMail (ConnectToHub). For authorized security testing, CTFs, and research only. (github_poc): https://github.com/CyberAlp0/SmarterMail-CVE-2026-24423
- SmarterMail - Remote Code Execution (nuclei): http/cves/2026/CVE-2026-24423.yaml

## Other vulnerabilities in SmarterTools SmarterMail

- [CVE-2025-52691](https://insights.sbomify.com/CVE-2025-52691/): SmarterTools SmarterMail Unrestricted Upload of File with Dangerous Type (critical 10.0, exploited in the wild)
- [CVE-2026-23760](https://insights.sbomify.com/CVE-2026-23760/): SmarterTools SmarterMail Authentication Bypass Using an Alternate Path or Channel (critical 9.3, exploited in the wild)
- [CVE-2021-32234](https://insights.sbomify.com/CVE-2021-32234/): Code injection in n/a (critical 9.8)
- [CVE-2019-7214](https://insights.sbomify.com/CVE-2019-7214/): Deserialization in n/a (critical 9.8)
- [CVE-2026-7807](https://insights.sbomify.com/CVE-2026-7807/): SmarterTools SmarterMail < Build 9560 Server Local File Inclusion via the /api/v1/report/summary/{type} API (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-24423 and fix it if it is affected.

What it is: CVE-2026-24423 is a critical command injection vulnerability in SmarterTools SmarterMail, published on 23 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2026-24423 in the wild since at least 5 Feb 2026, including in ransomware campaigns.

Affected product: SmarterTools SmarterMail. 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-2026-24423/ (Markdown: https://insights.sbomify.com/CVE-2026-24423/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-24423
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-24423
- OSV: https://osv.dev/vulnerability/CVE-2026-24423

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-24423/
Summaries are generated and may contain mistakes; the official description above is the record.