How severe is GHSA-mw2w-2hj2-fg8q?

GHSA-mw2w-2hj2-fg8q has a CVSS score of 8.1/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-mw2w-2hj2-fg8q?

GHSA-mw2w-2hj2-fg8q affects the following packages: yiisoft/yii (Packagist). Ecosystems affected: Packagist.

How do I fix GHSA-mw2w-2hj2-fg8q?

Update yiisoft/yii to 1.1.29 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mw2w-2hj2-fg8q is resolved across your whole dependency graph.

How do I detect GHSA-mw2w-2hj2-fg8q in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for yiisoft/yii. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-mw2w-2hj2-fg8q if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-mw2w-2hj2-fg8q?

O3 pinpoints whether GHSA-mw2w-2hj2-fg8q is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-mw2w-2hj2-fg8q actively exploited in the wild?

No public exploit code has been indexed for GHSA-mw2w-2hj2-fg8q yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-mw2w-2hj2-fg8q?

GHSA-mw2w-2hj2-fg8q has an EPSS (Exploit Prediction Scoring System) score of 3.1%, placing it in the 86th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was GHSA-mw2w-2hj2-fg8q published, and has it been updated?

GHSA-mw2w-2hj2-fg8q was published on November 14, 2023 and was last updated on February 16, 2024. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

GHSA-mw2w-2hj2-fg8q: yiisoft/yii Remote Code Execution (High 8.…

EPSS Exploitation Probability

via FIRST.org ↗

3.1%probability of exploitation in next 30 days

Lower Risk86th percentile-0.11%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

🐘yiisoft/yii

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

Impact

Affected versions of yiisoft/yii are vulnerable to Remote Code Execution (RCE) if the application calls unserialize() on arbitrary user input.

Patches

Upgrade yiisoft/yii to version 1.1.29 or higher.

For more information

See the following links for more details:

If you have any questions or comments about this advisory, contact us through security form.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`yiisoft/yii`	all versions	1.1.29

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for yiisoft/yii. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update yiisoft/yii to 1.1.29 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mw2w-2hj2-fg8q is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-mw2w-2hj2-fg8q is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-mw2w-2hj2-fg8q. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact Affected versions of `yiisoft/yii` are vulnerable to Remote Code Execution (RCE) if the application calls `unserialize()` on arbitrary user input. ### Patches Upgrade `yiisoft/yii` to version 1.1.29 or higher. ### For more information See the following links for more details: - [Git commit](https://github.com/yiisoft/yii/commit/37142be4dc5831114a375392e86d6450d4951c06) - https://owasp.org/www-community/vulnerabilities/PHP_Object_Injection If you have any questions or comments about this advisory, [contact us through security form](https://www.yiiframework.com/security).

O3 Security · Impact-Aware SCA

Is GHSA-mw2w-2hj2-fg8q in your dependencies?

O3 detects GHSA-mw2w-2hj2-fg8q across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works

GHSA-mw2w-2hj2-fg8q