CVE-2026-4015 in GPAC
Summary
by MITRE • 03/12/2026
A weakness has been identified in GPAC 26.03-DEV. Affected is the function txtin_process_texml of the file src/filters/load_text.c of the component TeXML File Parser. Executing a manipulation can lead to stack-based buffer overflow. It is possible to launch the attack on the local host. The exploit has been made available to the public and could be used for attacks. This patch is called d29f6f1ada5cc284cdfa783b6f532c7d8bd049a5. Applying a patch is advised to resolve this issue.
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Analysis
by VulDB Data Team • 03/17/2026
The vulnerability identified as CVE-2026-4015 represents a critical stack-based buffer overflow flaw within the GPAC media processing framework version 26.03-DEV. This weakness specifically affects the txtin_process_texml function located in the src/filters/load_text.c file, which forms part of the TeXML File Parser component. The vulnerability stems from inadequate input validation and bounds checking when processing TeXML formatted text files, creating an exploitable condition that allows attackers to overwrite adjacent stack memory locations. The flaw is particularly concerning because it can be exploited locally on the host system where GPAC is installed, eliminating the need for network-based attack vectors. Security researchers have confirmed that a public exploit exists for this vulnerability, making it immediately actionable by threat actors who may seek to leverage it for privilege escalation or arbitrary code execution within the context of the affected application.
The technical implementation of this vulnerability demonstrates a classic stack buffer overflow condition where insufficient bounds checking permits data to be written beyond the allocated buffer space. When the txtin_process_texml function processes malformed TeXML input, it fails to properly validate the length of incoming data before copying it into fixed-size stack buffers. This allows an attacker to craft malicious TeXML files that, when processed by GPAC, will overwrite adjacent stack memory including return addresses and function parameters. The vulnerability's classification aligns with CWE-121 Stack-based Buffer Overflow, which specifically addresses buffer overflows occurring in stack memory regions where the buffer is allocated on the stack and is susceptible to being overwritten by data exceeding its bounds. The attack surface is further expanded by the fact that this vulnerability operates within a media processing framework, meaning that any application or service using GPAC for text processing could potentially be compromised.
The operational impact of CVE-2026-4015 extends beyond simple local privilege escalation to encompass broader system compromise potential. Since the vulnerability can be exploited locally, attackers with user-level access to systems running GPAC could potentially elevate privileges or execute arbitrary code with the same privileges as the GPAC process. This is particularly dangerous in environments where GPAC is used for processing untrusted media content, such as in content management systems, media servers, or digital asset management platforms. The vulnerability's exploitation could lead to complete system compromise, data exfiltration, or persistent backdoor installation. According to ATT&CK framework methodology, this vulnerability maps to T1059 Command and Scripting Interpreter and T1068 Exploitation for Privilege Escalation, as the buffer overflow could be leveraged to execute malicious code with elevated privileges. The public availability of the exploit further amplifies the risk, as it reduces the barrier to entry for potential attackers and increases the probability of successful exploitation.
Mitigation strategies for CVE-2026-4015 should prioritize immediate patch application as the primary defense mechanism. The advisory references patch d29f6f6f1ada5cc284cdfa783b6f532c7d8bd049a5 which contains the necessary code modifications to resolve the buffer overflow condition. Organizations should implement comprehensive patch management procedures to ensure all instances of GPAC 26.03-DEV are updated promptly. In addition to patching, system administrators should consider implementing input validation controls at multiple levels including file format validation, size limitations, and content sanitization for TeXML files processed by GPAC. Network segmentation and privilege separation can help limit the potential impact of successful exploitation by reducing the attack surface. Monitoring for suspicious file processing activities and implementing intrusion detection systems can help identify exploitation attempts. Organizations should also consider disabling unnecessary text processing functionality when GPAC is used in production environments, particularly when processing untrusted content. The vulnerability highlights the importance of regular security assessments and code reviews for media processing frameworks, as these components often handle complex input parsing that creates numerous potential attack vectors.