# CVE-2026-25524: OpenMage LTS's Phar Deserialization leads to Remote Code Execution

> Attackers can achieve remote code execution by uploading malicious phar files disguised as images, triggering unsafe deserialization in OpenMage LTS.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 20 Apr 2026
- **Updated:** 20 Apr 2026
- **Also known as:** GHSA-fg79-cr9c-7369

## What is CVE-2026-25524?

CVE-2026-25524 is a high-severity unsafe deserialization vulnerability in OpenMage magento-lts, published on 20 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Magento Long Term Support (LTS) is an unofficial, community-driven project provides an alternative to the Magento Community Edition e-commerce platform with a high level of backward compatibility. Prior to version 20.17.0, PHP functions such as `getimagesize()`, `file_exists()`, and `is_readable()` can trigger deserialization when processing `phar://` stream wrapper paths. OpenMage LTS uses these functions with potentially controllable file paths during image validation and media handling. An attacker who can upload a malicious phar file (disguised as an image) and trigger one of these functions with a `phar://` path can achieve arbitrary code execution. Version 20.17.0 patches the issue.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2026-25524?

2 open source packages ship an affected version, including openmage/magento-lts. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `openmage/magento-lts` | Packagist | All versions | 20.17.0 |
| `openmage/magento-lts` | Packagist | All versions | 20.17.0 |

Products: Openmage Magento.

## How do I fix CVE-2026-25524?

Upgrade openmage/magento-lts to 20.17.0 or later.

## Is CVE-2026-25524 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-25524 exists.

Public exploit code:

- cve-2026-25524  Holds no customer payment data, no monitoring in place, monitored 24/7 The CVSS score is technically serious, but it doesn't tell how exposed it is, weather our existing defenses would stop or contain an attack. We should confirm the vulnerable component is reachable by untrust input in our environment. (github_poc): https://github.com/Emily-0309/unit-01-severity-vs-risk-reflection

## Other vulnerabilities in OpenMage magento-lts

- [CVE-2021-21426](https://insights.sbomify.com/CVE-2021-21426/): Fixes a bug in Zend Framework's Stream HTTP Wrapper (critical 9.8)
- [CVE-2021-21427](https://insights.sbomify.com/CVE-2021-21427/): Backport for CVE-2021-21024 Blind SQLi from Magento 2 (critical 9.1)
- [CVE-2021-41144](https://insights.sbomify.com/CVE-2021-41144/): OpenMage LTS authenticated remote code execution through layout update (high 8.8)
- [CVE-2026-40488](https://insights.sbomify.com/CVE-2026-40488/): OpenMage LTS has Customer File Upload Extension Blocklist Bypass that Leads to Remote Code Execution (high 8.7)
- [CVE-2020-15244](https://insights.sbomify.com/CVE-2020-15244/): RCE in Magento (high 8.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-25524 and fix it if it is affected.

What it is: CVE-2026-25524 is a high-severity unsafe deserialization vulnerability in OpenMage magento-lts, published on 20 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-25524 exists.

Affected packages and fixed versions:
- openmage/magento-lts (Packagist): affected all versions; fixed in 20.17.0
- openmage/magento-lts (Packagist): affected all versions; fixed in 20.17.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-25524/ (Markdown: https://insights.sbomify.com/CVE-2026-25524/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-25524
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-25524
- OSV: https://osv.dev/vulnerability/CVE-2026-25524

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-25524/
Summaries are generated and may contain mistakes; the official description above is the record.