CVE-2026-11525 (LOW): detected in Lambda Docker Images.

## CVE Details

| **CVE ID** | **Severity** | **Affected Package** | **Installed Version** | **Fixed Version** | **Date Published** | **Date of Scan** |
|-----------------|--------------|----------------------|-----------------------|-------------------|--------------------|------------------|
| [CVE-2026-11525](https://avd.aquasec.com/nvd/cve-2026-11525) | `LOW` | `undici` | `6.25.0` | `6.27.0, 7.28.0, 8.5.0` | `2026-06-17T18:17:35.097Z` | `2026-06-23T10:18:18.216181542Z` |

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## Affected Docker Images

| **Image Name** | **SHA** |
|-----------------------------|---------------------------------------|
| `public.ecr.aws/lambda/nodejs:24` | `public.ecr.aws/lambda/nodejs@sha256:904f7a98db07d37b59bf7edd90ed97bbba1cb574fd86db462205c68cfc55486c` |

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## Description

> Impact:
When undici parses a Set-Cookie header, it accepts any SameSite attribute value that contains Strict, Lax, or None as a substring, rather than the case-insensitive exact match specified by RFC 6265. Non-spec values are silently mapped to one of the three standard tokens. For example, SameSite=NoneOfYourBusiness is parsed as None (the most permissive setting), and SameSite=StrictLax is parsed as Lax (a downgrade from Strict).

Affected applications are those that consume Set-Cookie headers from server responses (for example via undici's fetch or proxy code paths) and then forward or rely on the parsed sameSite attribute. A malicious or non-compliant server can coerce the consumer's view of a cookie's SameSite policy to a weaker value, silently degrading the SameSite enforcement the cookie is supposed to provide.

This was introduced in undici 5.15.0 when the cookies feature was added.

Patches:
Upgrade to undici v6.26.0, v7.28.0 or v8.5.0.

Workarounds:
After parsing a Set-Cookie header, validate that the resulting sameSite attribute is one of 'Strict', 'Lax', or 'None' (exact, case-insensitive) before forwarding or relying on it.

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### Remediation Steps
- Update the affected package `undici` from version `6.25.0` to `6.27.0, 7.28.0, 8.5.0`.

### About this issue
- This issue may not contain all the information about the CVE nor the images it affects.
- This issue will not be updated with new information and the list of affected images may have changed since the creation of this issue.
- For more, visit [Lambda Watchdog](https://lambdawatchdog.com).
- This issue was created automatically by Lambda Watchdog.

Start by locating the build definitions for the public.ecr.aws/lambda/nodejs:24 image and checking how the undici dependency is selected. Update the affected dependency to a listed fixed version, then rebuild or scan the image and confirm that undici 6.25.0 is no longer present.

Written by the indexing model from the issue text.