CVE-2026-56377: ImageMagick Policy Bypass Allows Arbitrary File Creation

Technical summary

The vulnerability stems from an incorrect policy check in ImageMagick's file handling logic. When security policies are configured to restrict which files can be accessed or modified during image conversion operations, the implementation fails to properly enforce these restrictions. Remote attackers in a sandboxed conversion service context can bypass these path policy restrictions by crafting inputs that circumvent the validation, enabling arbitrary file creation or truncation outside the intended restricted directory. The flaw is classified under CWE-22 (Improper Limitation of a Pathname to a Restricted Directory), a path traversal weakness.

Business impact

Organizations running ImageMagick in sandboxed image conversion services face a containment breach risk. If an attacker can bypass file policy restrictions, they may write malicious files to unintended locations on the system, potentially enabling privilege escalation, code injection, or data exfiltration. The impact is most severe in multi-tenant environments or shared hosting scenarios where image processing is offered as a service. For enterprises using ImageMagick in air-gapped or controlled environments, the risk is lower but not negligible—an attacker with local access could still manipulate which files get created or modified, affecting application integrity or triggering denial-of-service conditions.

Affected systems

ImageMagick installations prior to version 7.1.2-24 are affected. This includes widely deployed versions across Linux distributions, container images, and embedded deployments. Organizations should inventory all systems running ImageMagick, particularly those exposed to untrusted image input or configured with custom security policies meant to restrict file access. Development environments, CI/CD pipelines, and serverless image processing functions that use ImageMagick are common deployment vectors.

Exploitability

Exploitation requires local or sandboxed-context access with user-level privileges; the attack vector is local (AV:L) and does not require user interaction. An attacker must be able to submit crafted image files or conversion requests to an ImageMagick service, then the policy check bypass allows them to write files outside policy boundaries. While this is not a remote code execution flaw and the CVSS score is low (3.3), the barrier to exploitation within a vulnerable service deployment is modest, and the impact scales with the criticality of the file paths being protected.

Remediation

Upgrade ImageMagick to version 7.1.2-24 or later. Verify the patch through the official ImageMagick release notes and your distribution's security advisories. In the interim, restrict local access to ImageMagick conversion services, run services under dedicated low-privilege accounts, and configure restrictive file system permissions on output directories. Review and tighten any custom security policies in place; consider disabling file write operations entirely if the conversion workflow does not require them.

Patch guidance

Apply the update to ImageMagick 7.1.2-24 or later as soon as practical within your change management process. Patch prioritization should account for whether your ImageMagick instances are exposed to untrusted input or configured with explicit file access policies. For systems in restricted internal networks with limited trust boundaries, patching can be scheduled in the next maintenance window. For internet-facing or multi-tenant services, prioritize patching within 1–2 weeks. Verify successful patching by confirming the installed version and testing that policy restrictions are enforced correctly in your environment before and after deployment.

Detection guidance

Monitor ImageMagick conversion logs for anomalous file creation or truncation attempts, particularly to paths outside the intended sandbox or policy-restricted directories. Watch for repeated policy violation attempts or error messages indicating policy check failures. If you have file integrity monitoring in place, configure it to alert on unexpected changes to critical directories. During vulnerability assessment, enumerate all ImageMagick deployments using asset discovery tools and version-checking scripts. Check /usr/bin/identify -version or equivalent on suspect systems. Security teams should also audit any custom ImageMagick policy files to understand which file paths are supposed to be protected, then validate that those policies are actually being enforced post-patch.

Why prioritize this

Although the CVSS score is low (3.3), prioritization depends on deployment context. Organizations running ImageMagick in sandboxed conversion services—especially public-facing or multi-tenant offerings—should treat this as moderate priority due to the breach-of-containment risk. Internal-use deployments or air-gapped environments can defer patching slightly but should not ignore it, as local attackers could still exploit the flaw to manipulate file creation. The lack of active public exploitation (KEV not listed) provides a small window for orderly patching before threat actors weaponize the vulnerability.

Risk score, explained

The CVSS 3.1 score of 3.3 reflects a low-severity local attack with limited impact: file integrity is at risk (I:L) but confidentiality and availability are not directly compromised by the flaw itself. The score assumes an attacker already has local access (low bar in sandboxed environments) and does not require interaction. However, the actual risk to your organization depends on whether ImageMagick processes untrusted input in a policy-restricted context; if it does, the operational risk may be meaningfully higher than the base score suggests. Contextualize this CVSS score against your specific threat model and deployment architecture.

Frequently asked questions