# CVE-2026-90513: simalexan api-lambda-send-email-ses API Gateway Endpoint template.yml SES.sendEmail missing authentication

> Attackers can send emails via the API Gateway endpoint without authentication, allowing unauthorized message dispatch and potential data exposure.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 13 Sep 2026
- **Updated:** 14 Sep 2026
- **Also known as:** GHSA-4cj2-3xxr-fv5p

## What is CVE-2026-90513?

CVE-2026-90513 is a medium-severity missing authorization vulnerability in simalexan api-lambda-send-email-ses, published on 13 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw has been found in simalexan api-lambda-send-email-ses up to bda6869aa81371d1e872242e74fe7d953edb818d. This issue affects the function SES.sendEmail of the file template.yml of the component API Gateway Endpoint. This manipulation of the argument toEmails/ccEmails/replyToEmails/subject/message causes missing authentication. It is possible to initiate the attack remotely. This product is using a rolling release to provide continious delivery. Therefore, no version details for affected nor updated releases are available. The project was informed of the problem early through an issue report but has not responded yet.

Weakness: CWE-306 (Missing Authentication for Critical Functionality), CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-90513?


## How do I fix CVE-2026-90513?

No fix has been published for CVE-2026-90513 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-90513 being exploited?

There is no known exploitation of CVE-2026-90513 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90513 and fix it if it is affected.

What it is: CVE-2026-90513 is a medium-severity missing authorization vulnerability in simalexan api-lambda-send-email-ses, published on 13 Sep 2026. 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-2026-90513 in the wild and no public exploit code.

Affected product: simalexan api-lambda-send-email-ses. 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-2026-90513/ (Markdown: https://insights.sbomify.com/CVE-2026-90513/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90513
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90513
- OSV: https://osv.dev/vulnerability/CVE-2026-90513

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90513/
Summaries are generated and may contain mistakes; the official description above is the record.