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

3.1 lowEPSS 0.2%Fix available

Low (3.1) in rails rails. EPSS 0.2% estimated probability of exploitation activity in the next 30 days. Fixed in actionpack 8.0.5.2, 8.1.4.1.

On this page
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.

Severity

CVSS 3.1

3.1 low
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N
EPSS
0.2% estimated probability of exploitation activity in the next 30 days; 6th percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
CISA's assessment (SSVC)
Exploitation: none · Automatable: no · Technical impact: partial, assessed 2026-11-13. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
CWE
CWE-352 Cross-Site Request Forgery (Cross Site Reference Forgery)
OWASP Top 10
A01:2025 Broken Access Control
Published
Modified
Assigned by
GitHub_M (CNA)
NVD analysis
Awaiting analysis
Record from
the NVD, synced

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Affected

Versions

From the CNA's record in the CVE List.

ProductAffected
rails>= 8.1, < 8.1.4.1
rails< 8.0.5.2

Fix and patched versions

  • actionpack (RubyGems): fixed in 8.1.4.1, 8.0.5.2

Packages (OSV)

AdvisoryEcosystemPackageAffectedFixed in
GHSA-gmj8-hvj3-49mwRubyGemsactionpack>=8.1.0.beta1 <8.1.4.18.1.4.1
GHSA-gmj8-hvj3-49mwRubyGemsactionpack<8.0.5.28.0.5.2

Linux distributions

DistributionReleasePackageFixed inAdvisory
Debian12, 13, 14railsno fix listedDEBIAN-CVE-2026-126067
Ubuntu24.04:LTS, 26.04:LTS, 26.10 and 4 morerailsno fix listedUBUNTU-CVE-2026-126067

From the distributions' data via OSV.dev: the Debian Security Tracker; Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian · Ubuntu.

Attack patterns (CAPEC)

  • CAPEC-62 Cross Site Request Forgery Likelihood: High · Severity: Very High
  • CAPEC-111 JSON Hijacking (aka JavaScript Hijacking) Likelihood: High · Severity: High
  • CAPEC-462 Cross-Domain Search Timing Severity: Medium
  • CAPEC-467 Cross Site Identification Severity: Low

The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.

References

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