CVE-2026-102639 in MobilityDB
Summary
by MITRE • 09/29/2026
MobilityDB version 1.3.0 and earlier contains an out-of-bounds read vulnerability in the MEOS binary and library WKB deserialization logic that allows unprivileged database users to crash the PostgreSQL backend process by supplying a crafted WKB payload with a negative length field. The negative length value wraps to a large unsigned size_t due to missing signed validation, bypasses an overflow-unsafe pointer arithmetic bounds check in wkb_parse_state_check(), and causes memcpy() in text_from_wkb_state() to operate with a corrupted unbounded length, resulting in a remote denial-of-service condition affecting all sessions on the PostgreSQL instance.
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Analysis
by VulDB Data Team • 09/29/2026
The vulnerability identified in MobilityDB versions 1.3.0 and earlier represents a critical security flaw within the MEOS binary and library components responsible for Well-Known Binary (WKB) deserialization. This issue specifically targets the handling of spatial data formats, which are commonly used to represent geometric objects such as points, lines, and polygons in database systems. The core technical deficiency lies in the absence of proper signed integer validation during the parsing process. When a user supplies a crafted WKB payload containing a negative length field, the system fails to detect this invalid input before proceeding with memory operations. This lack of validation allows an unprivileged database user to exploit the flaw without requiring elevated privileges, highlighting a significant gap in access control and input sanitization mechanisms within the application logic.
From a technical perspective, the exploitation mechanism relies on integer type conversion weaknesses inherent in C-based systems. The negative length value provided by the attacker is interpreted as a large unsigned size_t due to missing signed validation checks. This arithmetic wrap-around effectively bypasses an overflow-unsafe pointer arithmetic bounds check located within the wkb_parse_state_check() function. Consequently, subsequent memory operations proceed with corrupted parameters that do not reflect the actual available buffer space or intended data boundaries. The critical failure occurs in the text_from_wkb_state() function, where a memcpy operation is executed using this unbounded length value. This results in an out-of-bounds read condition, as the system attempts to copy data from memory locations beyond the allocated buffer limits, leading to undefined behavior and immediate instability within the database process.
The operational impact of this vulnerability is severe, primarily manifesting as a remote denial-of-service (DoS) attack vector against PostgreSQL instances running MobilityDB. Because the flaw causes the backend process to crash upon processing the malicious payload, it disrupts service availability for all active sessions connected to that specific instance. This means that even if only one user initiates the attack, the resulting instability affects every other legitimate user attempting to interact with the database at that time. The ability of unprivileged users to trigger such a catastrophic failure underscores the importance of robust input validation in multi-tenant environments where resource isolation and stability are paramount for maintaining service continuity and data integrity across diverse user groups.
In terms of industry standard classifications, this vulnerability aligns closely with CWE-125, which describes Out-of-bounds Read conditions resulting from improper boundary checks on memory access operations. Additionally, the exploitation technique relates to CWE-190, Integer Overflow or Wraparound, as the negative value wrapping into a large unsigned integer is the primary enabler of the subsequent buffer overflow logic bypass. From an offensive security perspective, this attack vector corresponds to ATT&CK techniques involving resource hijacking and denial-of-service via application layer exploitation, specifically leveraging input validation failures to disrupt system availability rather than compromising confidentiality or integrity directly at the point of entry.
Mitigation strategies should prioritize immediate patching to the latest stable version of MobilityDB where these deserialization flaws have been addressed by developers through rigorous input sanitization and strict type checking implementations. Administrators must ensure that all instances are updated to versions released after the discovery of this vulnerability, as earlier builds remain susceptible to exploitation via crafted WKB payloads. Furthermore, implementing network-level access controls can provide an additional layer of defense by restricting direct database connectivity to trusted IP ranges or application servers only, thereby reducing the attack surface available to unprivileged users who might attempt such exploits. Regular security audits focusing on spatial data handling routines and adherence to secure coding standards for C-based extensions are also recommended to prevent similar issues in future development cycles.