CVE-2026-77093 in Cloud
Summary
by MITRE • 10/13/2026
CvFWD contained an integer overflow affecting service availability. Software customers upgrade to resolved maintenance release. Update all Commvault installations, including CommServe, Webserver, Command Center, MediaAgents, Clients and HyperScale
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 10/13/2026
The vulnerability identified in CvFWD involves a critical integer overflow condition that directly impacts the operational stability of the software environment. Integer overflows occur when an arithmetic operation results in a value exceeding the maximum limit for the data type used to store it, causing the number to wrap around or become negative due to how binary representation handles boundary conditions. In this specific instance within CvFWD, such miscalculations lead to improper memory allocation or logic errors that disrupt normal service execution. This flaw is not merely a theoretical concern but manifests as a tangible threat to system availability, potentially causing the affected services to crash, hang, or become unresponsive under certain triggering conditions.
From an operational perspective, this vulnerability poses a significant risk to business continuity for organizations relying on Commvault infrastructure. Since CvFWD is integral to data management workflows, its instability can interrupt backup and recovery operations, leading to potential data loss or extended downtime during critical maintenance windows. The impact extends beyond the immediate service failure; it undermines trust in the reliability of automated protection mechanisms. Attackers could potentially exploit this flaw through crafted inputs that trigger the overflow condition, resulting in a denial-of-service scenario where legitimate users are unable to access essential storage and management functions.
This issue aligns with Common Weakness Enumeration (CWE) category CWE-190, which defines integer overflow or wraparound errors. Such weaknesses often serve as precursors to more severe vulnerabilities like buffer overflows if the resulting incorrect values lead to out-of-bounds memory writes. Furthermore, in the context of the MITRE ATT&CK framework, this vulnerability relates to techniques involving resource exhaustion and service disruption, specifically falling under tactics that aim to impact availability rather than confidentiality or integrity directly. The exploitation vector likely involves providing malformed data packets or specific command sequences that force the application into an invalid state through arithmetic miscalculation.
To mitigate this risk, immediate action is required across all components of the Commvault ecosystem. Customers must upgrade their installations to the resolved maintenance release provided by the vendor. This update addresses the underlying code logic responsible for the integer calculation errors within CvFWD. It is imperative that administrators apply patches not only to the primary management servers but also to peripheral nodes including Webserver, Command Center, MediaAgents, Clients, and HyperScale instances. A comprehensive patching strategy ensures that no node in the distributed architecture remains vulnerable to exploitation via this specific overflow mechanism. Regular monitoring of vendor advisories and maintaining an up-to-date inventory of all deployed components are essential practices for sustaining long-term security posture against such structural software defects.