CVE-2026-109279 in ImageMagick
Summary
by MITRE • 10/12/2026
ImageMagick before 6.9.13-57 and 7.x before 7.1.2-32 lacks proper synchronization when the security policy is accessed, so simultaneous reads and writes of the policy by multiple threads trigger a race condition that causes a heap buffer over-write. An attacker able to induce concurrent security policy access can crash the application, causing a denial of service.
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Analysis
by VulDB Data Team • 10/12/2026
The vulnerability identified in ImageMagick versions prior to 6.9.13-57 and 7.x before 7.1.2-32 represents a critical concurrency flaw rooted in improper synchronization mechanisms within the security policy subsystem. This issue, classified under CWE-362 as a Concurrent Execution using Shared Resource with Improper Synchronization Race Condition, arises when multiple threads attempt to access or modify the application's security policies simultaneously without adequate locking primitives. The core technical failure lies in the lack of mutual exclusion during read and write operations on shared policy data structures. When one thread is in the process of updating a policy setting while another thread reads from it, the memory layout can become corrupted due to unsynchronized access patterns. This specific race condition manifests as a heap buffer over-write, which occurs when the application attempts to write data beyond the allocated boundaries of a heap-allocated buffer because the state assumed by the writing thread is no longer valid or consistent with reality due to concurrent modifications by another thread.
The operational impact of this vulnerability is primarily centered on service availability and system stability rather than direct remote code execution, although the potential for exploitation cannot be entirely dismissed in complex environments. An attacker who can induce concurrent access to the security policy functionality through crafted requests or automated multi-threaded interactions can trigger the race condition reliably enough to corrupt memory structures. This corruption typically results in application crashes, leading to a denial of service where legitimate users are unable to process images or utilize the ImageMagick services hosted by the vulnerable software. In scenarios where the affected binary is running with elevated privileges or handling sensitive data, such instability could indirectly compromise integrity if the heap overflow allows for further exploitation techniques like arbitrary write primitives, though the primary documented impact remains the disruption of service through crashes.
From a threat intelligence perspective, this vulnerability aligns with ATT&CK technique T1499 Endpoint Denial of Service, specifically under sub-techniques involving resource exhaustion or application crash via memory corruption. The attack vector typically requires network-accessible services that expose ImageMagick processing capabilities to untrusted input, allowing adversaries to flood the service with concurrent requests designed to hit the race window. Mitigation strategies must prioritize immediate patching by upgrading to version 6.9.13-57 or later for the legacy branch and version 7.1.2-32 or later for the modern branch, as these releases include the necessary synchronization fixes such as mutex locks around policy access routines. For organizations unable to upgrade immediately due to dependency constraints, implementing strict rate limiting on image processing endpoints can reduce the probability of concurrent collisions. Additionally, deploying Web Application Firewalls with rules that detect and block anomalous patterns of rapid, parallel requests targeting configuration or policy-related API endpoints may provide a temporary layer of defense against exploitation attempts while permanent remediation is planned.