# CVE-2021-39426: Code injection in n/a

> Attackers can execute arbitrary PHP code in Seacms via the notify1 parameter in the admin notification script.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Dec 2022
- **Updated:** 21 Apr 2025
- **Also known as:** GHSA-7mc2-wwmp-gcxh

## What is CVE-2021-39426?

CVE-2021-39426 is a critical code injection vulnerability in Seacms Seacms, published on 15 Dec 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in /Upload/admin/admin_notify.php in Seacms 11.4 allows attackers to execute arbitrary php code via the notify1 parameter when the action parameter equals set.

Weakness: CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2021-39426?

It affects 1 product.


Products: Seacms Seacms.

## How do I fix CVE-2021-39426?

No fix has been published for CVE-2021-39426 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-39426 being exploited?

There is no known exploitation of CVE-2021-39426 in the wild and no public exploit code.

## Other vulnerabilities in Seacms Seacms

- [CVE-2025-44073](https://insights.sbomify.com/CVE-2025-44073/): SQL injection in n/a (critical 9.8)
- [CVE-2025-44071](https://insights.sbomify.com/CVE-2025-44071/): Code injection in n/a (critical 9.8)
- [CVE-2025-44072](https://insights.sbomify.com/CVE-2025-44072/): SQL injection in n/a (critical 9.8)
- [CVE-2025-44074](https://insights.sbomify.com/CVE-2025-44074/): SQL injection in n/a (critical 9.8)
- [CVE-2025-29647](https://insights.sbomify.com/CVE-2025-29647/): SQL injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-39426 and fix it if it is affected.

What it is: CVE-2021-39426 is a critical code injection vulnerability in Seacms Seacms, published on 15 Dec 2022. 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-2021-39426 in the wild and no public exploit code.

Affected product: Seacms Seacms. 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-2021-39426/ (Markdown: https://insights.sbomify.com/CVE-2021-39426/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-39426
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-39426
- OSV: https://osv.dev/vulnerability/CVE-2021-39426

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-39426/
Summaries are generated and may contain mistakes; the official description above is the record.