# CVE-2026-126067: Action Pack: Missing SameSite attribute on session cookies from Action Pack session stores

Source: https://junglewise.ai/threats/cve-2026-126067-action-pack-is-a-framework-for-handling-and-responding-to-web  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-10  
License: CC BY 4.0 with a link back

CVE-2026-126067 · Severity: low · CVSS 3.1 · Published 2026-11-10

Action Pack is a framework for handling and responding to web requests. Prior to 8.1.4.1 and 8.0.5.2, Action Pack session stores other than ActionDispatch::Session::CookieStore (CacheStore, MemCacheStore, and third-party stores built on AbstractStore, AbstractSecureStore or the session mixins) write the session cookie without a SameSite attribute, regardless of config.action_dispatch.cookies_same_site_protection, which defaults to :lax. Only CookieStore applies the configured policy. In browsers that do not treat a cookie without the attribute as SameSite=Lax, a cross-site request could carry the session cookie, possibly leading to cross-site request forgery against actions that do not verify an authenticity token, such as those of API-only applications. Applications are affected when they use a session store other than CookieStore and do not pass same_site: to config.session_store. This issue is fixed in versions 8.1.4.1 and 8.0.5.2.

Technologies: [actionpack (RubyGems)](https://junglewise.ai/threats/technologies/actionpack). Vendors: [RubyGems](https://junglewise.ai/threats/vendors/rubygems).

## Quick answers

**Is CVE-2026-126067 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-126067 being exploited in the wild.

**How severe is CVE-2026-126067?** Low severity, with a CVSS score of 3.1, published 10 November 2026.

**Which products and versions are affected?** actionpack (RubyGems) >= 8.1.0.beta1, < 8.1.4.1, ECOSYSTEM:introduced=8.1.0.beta1,fixed=8.1.4.1.

**Is there a fix for CVE-2026-126067?** Yes. actionpack (RubyGems): upgrade to 8.1.4.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2026-126067?** Check whether you run actionpack (RubyGems) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- actionpack (RubyGems): upgrade to 8.1.4.1 or later

  ```sh
  bundle update actionpack
  ```


## Affected products

- actionpack (RubyGems) >= 8.1.0.beta1, < 8.1.4.1, ECOSYSTEM:introduced=8.1.0.beta1,fixed=8.1.4.1

## Identifiers

- CVE-2026-126067
- GHSA-gmj8-hvj3-49mw

## Related threats

- [Rails Action Pack remote IP spoofing in request handling](https://junglewise.ai/threats/cve-2026-126083-action-pack-is-a-framework-for-handling-and-responding-to-web)
- [Rails Action Pack mass assignment bypass in Parameters#each_key](https://junglewise.ai/threats/cve-2026-126081-action-pack-is-a-framework-for-handling-and-responding-to-web)
- [Rails Action Pack session cookie exposure in cached responses](https://junglewise.ai/threats/cve-2026-126077-action-pack-is-a-framework-for-handling-and-responding-to-web)
- [Ruby on Rails Action Pack session restoration after logout](https://junglewise.ai/threats/cve-2026-126076-action-pack-is-a-framework-for-handling-and-responding-to-web)
- [Rails Action Pack cache poisoning via content-type negotiation](https://junglewise.ai/threats/cve-2026-126073-action-pack-is-a-framework-for-handling-and-responding-to-web)