Reflected Cross-site Scripting in yiisoft/yii2 Debug mode

Exploitation

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

CVSS

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

EPSS

• CVE-2024-32877: 0.35% estimated exploitation activity in the next 30 days; percentile 28.37 (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.

During the internal penetration testing of our product based on Yii2, we discovered an XSS vulnerability within the framework itself. This issue is relevant for the latest version of Yii2 (2.0.49.3). Conditions for vulnerability reproduction The framework is in debug mode (YIIDEBUG set to true). The php.ini setting zend.exceptionignoreargs is set to Off (default value). An attacker induces an exception in the application, leading to a stack trace page being displayed. Vulnerability description The issue lies in the mechanism for displaying function argument values in the stack trace. The vulnerability manifests when an argument's value exceeds 32 characters. For convenience, argument values exceeding this limit are truncated and displayed with an added "...". The full argument value becomes visible when hovering over it with the mouse, as it is displayed in the title attribute of a span tag. However, the use of a double quote (") allows an attacker to break out of the title…

Published by the source

2 Jun 2024, 22:27 UTC

Last modified by the source

8 Jul 2024, 19:06 UTC

Source last checked

26 Oct 2026, 14:25 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-qg5r-95m4-mjgj

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# Patch Next advisory brief: CVE-2024-32877

Advisory: Reflected Cross-site Scripting in yiisoft/yii2 Debug mode
IDs: CVE-2024-32877, GHSA-qg5r-95m4-mjgj
Record: https://patchnext.com/advisories/cve-2024-32877 (revision 1, source checked 26 Oct 2026, 14:25 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.2)
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 >= 2.0.43, < 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-qg5r-95m4-mjgj (GitHub-reviewed advisory GHSA-qg5r-95m4-mjgj lists affected ranges: Packagist yiisoft/yii2 >=2.0.43 <2.0.49.4)

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