CVE-2026-95116 in libming
Summary
by MITRE • 10/08/2026
An issue in libming through 0.4.8 allows a remote attacker to cause a denial of service via the readtag_file() in src/blocks/fromswf.c.
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Analysis
by VulDB Data Team • 10/08/2026
The vulnerability identified in libming versions up to and including 0.4.8 represents a critical security flaw within the library's SWF file parsing logic, specifically located in the readtag_file function found in the source file src/blocks/fromswf.c. Libming is an open-source C library designed for reading, writing, and manipulating Macromedia Flash (SWF) files, which are widely used for vector graphics, animations, and interactive content on the web. The core issue stems from insufficient validation of input data during the processing of SWF tags, allowing a remote attacker to craft maliciously formatted or corrupted SWF files that trigger abnormal behavior within the application utilizing libming. This flaw is primarily categorized under CWE-20 Improper Input Validation, as the library fails to adequately check the integrity and bounds of the data structures it processes before attempting to read them into memory.
The technical mechanism behind this denial-of-service vulnerability involves the manipulation of tag headers or content within a SWF file that causes the readtag_file function to enter an infinite loop, consume excessive system resources such as CPU cycles or memory, or crash due to invalid pointer dereferences and buffer overflows. When libming processes a specially crafted SWF file containing malformed tags, the internal state machine responsible for parsing these elements may become desynchronized or stuck in a repetitive execution path that never terminates correctly. This behavior prevents the application from continuing its normal operations effectively, leading to a complete halt of service for users relying on the affected software. The impact is particularly severe because SWF files are often downloaded from untrusted sources via web browsers or embedded in documents, making them an attractive vector for automated attacks against systems that process user-uploaded media content.
From an operational perspective, this vulnerability can be exploited by a remote attacker to disrupt services without requiring authentication, provided the target system processes maliciously crafted SWF files through libming. This could affect web servers hosting Flash-based applications, document viewers supporting multimedia attachments, or any custom application integrating libming for SWF analysis. The resulting denial of service degrades availability, which is one of the three pillars of information security alongside confidentiality and integrity. In environments where high uptime is critical, such as enterprise portals or public-facing media platforms, this vulnerability poses a significant risk to business continuity and user trust. Attackers can leverage automated tools to scan for systems using vulnerable versions of libming and launch distributed denial-of-service attacks by flooding targets with malformed SWF payloads that trigger the flaw in readtag_file.
To mitigate this risk, organizations must immediately upgrade libming to version 0.4.9 or later, where these input validation issues have been addressed through rigorous testing and code hardening efforts. If upgrading is not feasible due to legacy system constraints, implementing strict file type verification at the network perimeter using deep packet inspection can help block malicious SWF files before they reach the application layer. Additionally, deploying sandboxing techniques for processing untrusted media content ensures that any potential crashes or resource exhaustion are contained within isolated environments rather than affecting the host system. Security teams should also monitor logs for unusual spikes in CPU usage or memory consumption associated with multimedia processing services, which may indicate an ongoing exploitation attempt. Regular vulnerability assessments and adherence to secure coding standards such as those outlined by OWASP can further reduce exposure to similar input validation flaws in future development cycles.