CVE-2025-52886 in Poppler
Summary
by MITRE • 07/02/2025
Poppler is a PDF rendering library. Versions prior to 25.06.0 use `std::atomic_int` for reference counting. Because `std::atomic_int` is only 32 bits, it is possible to overflow the reference count and trigger a use-after-free. Version 25.06.0 patches the issue.
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Analysis
by VulDB Data Team • 10/11/2025
The vulnerability identified as CVE-2025-52886 affects Poppler, a widely-used PDF rendering library that serves as the foundation for numerous applications including web browsers, document viewers, and content management systems. This security flaw resides in the library's reference counting mechanism, which is critical for memory management in object-oriented software architectures. The vulnerability specifically impacts versions prior to 25.06.0, where the implementation employs `std::atomic_int` for managing reference counts, creating a significant attack surface that can be exploited by malicious actors.
The technical root cause of this vulnerability stems from the use of a 32-bit atomic integer for reference counting operations. In memory management systems, reference counting is a fundamental technique where each object maintains a counter tracking how many references point to it. When the counter reaches zero, the object is safely deallocated. However, when using `std::atomic_int` which is limited to 32 bits, the reference count can overflow when incremented beyond the maximum value of a 32-bit signed integer, which is 2,147,483,647. This overflow condition creates a scenario where the reference count wraps around to a negative value or zero, leading to premature object deallocation.
The operational impact of this vulnerability is severe and directly aligns with CWE-190, which describes integer overflow conditions. An attacker can exploit this by carefully crafting PDF documents that trigger excessive reference counting operations, ultimately causing a use-after-free condition where freed memory is accessed. This type of vulnerability can result in arbitrary code execution, denial of service, or information disclosure, depending on the specific implementation details and attack vector. The attack surface is particularly concerning given Poppler's integration into numerous applications, potentially affecting millions of end users.
The mitigation strategy involves upgrading to Poppler version 25.06.0 or later, which addresses the issue by implementing proper reference counting mechanisms that prevent overflow conditions. Organizations should prioritize this update across all systems utilizing Poppler, particularly those handling untrusted PDF content. The fix demonstrates adherence to secure coding practices outlined in the ATT&CK framework under defense evasion techniques, where memory corruption vulnerabilities are commonly exploited. Additionally, this vulnerability highlights the importance of proper integer handling and overflow prevention in security-critical software components, reinforcing the need for comprehensive testing and validation of memory management systems.