Answer in brief
CVE-2026-126081 records a High severity (CVSS 7.5) vulnerability in Action Pack: Possible Strong Parameters bypass in Parameters#each_key. The current sources do not mark it as known exploited. The current feed maps rails/rails (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps rails/rails (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| rails/railsgeneric | >=8.1 <8.1.4.1 || <8.0.5.2 | 8.0.5.2, 8.1.4.1 |
Published upstream
Nov 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 10, 2026
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.
Quoted source text, attributed separately from HOL analysis.