# CVE-2025-62380: Mailgen has HTML Injection and XSS Filter Bypass in Plaintext Emails

> Attacker can inject HTML into plaintext emails via Unicode bypass, leading to script execution in victim's browser if rendered as HTML.

- **Severity:** Low 2.9 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Oct 2025
- **Updated:** 15 Oct 2025
- **Also known as:** GHSA-q4w9-x3rv-4c8j

## What is CVE-2025-62380?

CVE-2025-62380 is a low-severity cross-site scripting vulnerability in eladnava mailgen, published on 15 Oct 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

mailgen is a Node.js package that generates responsive HTML e-mails for sending transactional mail. Mailgen versions through 2.0.31 contain an HTML injection vulnerability in plaintext emails generated with the generatePlaintext method when user generated content is supplied. The plaintext generation code attempts to strip HTML tags using a regular expression and then decodes HTML entities, but tags that include certain Unicode line separator characters are not matched and removed. These encoded tags are later decoded into valid HTML content, allowing unexpected HTML to remain in output intended to be plaintext. Projects are affected if they call Mailgen.generatePlaintext with untrusted input and then render or otherwise process the returned string in a context where HTML is interpreted. This can lead to execution of attacker supplied script in the victim’s browser. Version 2.0.32 fixes the issue.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2025-62380?

2 open source packages ship an affected version, including mailgen.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mailgen` | npm | All versions | 2.0.32 |
| `mailgen` | npm | All versions | 2.0.32 |

## How do I fix CVE-2025-62380?

Upgrade mailgen to 2.0.32 or later.

## Is CVE-2025-62380 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-62380 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-62380 and fix it if it is affected.

What it is: CVE-2025-62380 is a low-severity cross-site scripting vulnerability in eladnava mailgen, published on 15 Oct 2025. 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-2025-62380 exists.

Affected packages and fixed versions:
- mailgen (npm): affected all versions; fixed in 2.0.32
- mailgen (npm): affected all versions; fixed in 2.0.32

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-2025-62380/ (Markdown: https://insights.sbomify.com/CVE-2025-62380/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-62380
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-62380
- OSV: https://osv.dev/vulnerability/CVE-2025-62380

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-62380/
Summaries are generated and may contain mistakes; the official description above is the record.