CVE-2026-93313 in Poppler
Summary
by MITRE • 09/18/2026
A vulnerability was found in Freedesktop Poppler 26.07.0. The impacted element is the function JBIG2Stream::readCodeTableSeg of the file poppler/JBIG2Stream.cc. Performing a manipulation results in integer overflow. The attack can be initiated remotely. The exploit has been made public and could be used. The patch is named eb87cf711563894649bd0c365baa479401dc6d51. To fix this issue, it is recommended to deploy a patch.
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Analysis
by VulDB Data Team • 09/18/2026
The Freedesktop Poppler library, specifically version 26.07.0 and potentially earlier versions, contains a critical security flaw within its JBIG2 image decoding component. The vulnerability resides in the readCodeTableSeg function located in the poppler/JBJB2Stream.cc source file. This specific code segment is responsible for processing data segments related to JBIG2 compression standards, which are commonly used in PDF documents and other digital formats containing scanned images or text-heavy graphics. When an attacker provides a specially crafted input that triggers this function with manipulated parameters, it results in an integer overflow condition. This type of flaw occurs when the arithmetic operation exceeds the maximum value that can be stored in the allocated variable size, leading to unexpected behavior such as wrapping around to negative numbers or truncating data incorrectly.
From a technical perspective, this vulnerability is classified under CWE-190, which denotes Integer Overflow or Wraparound. The root cause lies in insufficient validation of input values before they are used in arithmetic calculations within the readCodeTableSeg function. Because JBIG2 decoding involves complex table lookups and memory allocations based on calculated sizes, an integer overflow can lead to a mismatch between the allocated buffer size and the actual data being processed. This discrepancy often results in heap-based buffer overflows or out-of-bounds writes when subsequent operations attempt to write beyond the bounds of the incorrectly sized allocation. The presence of this flaw allows for potential memory corruption, which is a precursor to more severe exploitation scenarios including arbitrary code execution if combined with other techniques like return-oriented programming (ROP) chains.
The operational impact of this vulnerability is significant due to its remote exploitability and public availability. Attackers can initiate the attack remotely by distributing malicious PDF documents or images that contain crafted JBIG2 streams designed to trigger the integer overflow upon parsing. Since Poppler is widely used as a rendering engine in many popular applications such as web browsers, document viewers, and enterprise content management systems, users of these applications are at risk simply by opening a compromised file. The fact that an exploit has been made public increases the likelihood of widespread automated attacks targeting unpatched systems. Successful exploitation could lead to denial of service through application crashes or, more critically, remote code execution allowing full compromise of the victim's system depending on the privileges under which the vulnerable application is running.
In terms of threat intelligence and attack frameworks, this vulnerability aligns with MITRE ATT&CK techniques related to initial access via malicious files and subsequent exploitation for privilege escalation or persistence if combined with other vulnerabilities. It represents a classic example of how parsing flaws in widely deployed libraries can serve as an entry point into otherwise secure environments. Organizations relying on Poppler must recognize that the public disclosure of exploits significantly lowers the barrier to entry for attackers, making timely remediation essential rather than optional.
To mitigate this risk, it is imperative to apply the patch identified by commit hash eb87cf711563894649bd0c365baa479401dc6d51 as soon as possible. This patch addresses the integer overflow issue within the readCodeTableSeg function by implementing proper bounds checking and validation of input values before arithmetic operations are performed. Administrators should update their Poppler installations to a version that includes this fix or later. Additionally, organizations should consider deploying web application firewalls (WAFs) with rules capable of detecting anomalous JBIG2 stream patterns if immediate patching is not feasible. Regular security audits and static code analysis tools configured to detect integer overflow vulnerabilities can also help identify similar issues in other parts of the codebase before they are exploited in production environments.