Improperly Controlled Modification of Dynamically-Determined Object Attributes Affecting rails package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DEBIAN13-RAILS-22421957
- published11 Nov 2026
- disclosed10 Nov 2026
Introduced: 10 Nov 2026
NewCVE-2026-126081 (opens in a new tab)How to fix?
There is no fixed version for Debian:13 rails.
NVD Description
Note: Versions mentioned in the description apply only to the upstream rails package and not the rails package as distributed by Debian.
See How to fix? for Debian:13 relevant fixed versions and status.
Action Pack is a framework for handling and responding to web requests. Prior to 8.1.4.1 and 8.0.5.2, ActionController::Parameters#each_key delegates to the internal ActiveSupport::HashWithIndifferentAccess that holds the request parameters, so when called with a block it returns that hash instead of the Parameters instance. The hash does not respond to permitted?, so Active Model mass assignment (new, assign_attributes, update) accepts it without raising ActiveModel::ForbiddenAttributesError. An application that passes the return value of each_key to mass assignment could allow a remote, unauthenticated attacker to set attributes that the application does not permit, such as an authorization flag. This is an incomplete fix of CVE-2020-8164, which made each, each_pair and each_value return the Parameters instance but left each_key delegated. An application is affected if it passes the return value of ActionController::Parameters#each_key, called with a block, to mass assignment. Rails itself makes no such call. This issue is fixed in versions 8.1.4.1 and 8.0.5.2.
References
- https://security-tracker.debian.org/tracker/CVE-2026-126081
- https://github.com/rails/rails/commit/2fc8838300133931e19eed3ea6cee76a7e83f19c
- https://github.com/rails/rails/commit/8ba746e0a786458c281060823f2ccc5c5f6312ac
- https://github.com/rails/rails/releases/tag/v8.0.5.2
- https://github.com/rails/rails/releases/tag/v8.1.4.1
- https://github.com/rails/rails/security/advisories/GHSA-wm3x-v3qw-4jh3