Unsafe Reflection in base Component class in yiisoft/yii2

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.1 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2024-4990: 80.10% estimated exploitation activity in the next 30 days; percentile 99.62 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Yii2 supports attaching Behaviors to Components by setting properties having the format 'as <behaviour-name'. Internally this is done using the set() magic method. If the value passed to this method is not an instance of the Behavior class, a new object is instantiated using Yii::createObject($value). However, there is no validation check that verifies that $value is a valid Behavior class name or configuration. An attacker that can control the content of the $value variable can then instantiate arbitrary classes, passing parameters to their constructors and then invoking setter methods. Impact With some effort malicious code can be injected executed which might be anything ranging from deleting files to dropping database tables Patches Not yet patched. Workarounds No Work around available References Reported Here in case the link is dead, here is the full description Description Yii2 supports attaching Behaviors to Components by setting properties having the format 'as…

Published by the source

2 Jun 2024, 22:30 UTC

Last modified by the source

20 Mar 2025, 19:38 UTC

Source last checked

26 Oct 2026, 14:30 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-cjcc-p67m-7qxm

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# Patch Next advisory brief: CVE-2024-4990

Advisory: Unsafe Reflection in base Component class in yiisoft/yii2
IDs: CVE-2024-4990, GHSA-cjcc-p67m-7qxm
Record: https://patchnext.com/advisories/cve-2024-4990 (revision 1, source checked 26 Oct 2026, 14:30 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: yiisoft/yii2 2.0.49.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist yiisoft/yii2: affected < 2.0.49.4; fixed in 2.0.49.4

## Suggested inspection (read-only)
- Packagist yiisoft/yii2: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on yiisoft/yii2.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-cjcc-p67m-7qxm (GitHub-reviewed advisory GHSA-cjcc-p67m-7qxm lists affected ranges: Packagist yiisoft/yii2 >=0 <2.0.49.4)

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