CVE-2026-117350 in Bitcoin Core
Summary
by MITRE • 10/30/2026
Bitcoin Core prior to 29.5, 30.4, 31.2 and 32.1 is vulnerable to an OOM issue.
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Analysis
by VulDB Data Team • 10/30/2026
The vulnerability identified in Bitcoin Core versions prior to 29.5, 30.4, 31.2, and 32.1 represents a critical resource exhaustion flaw that can lead to a denial of service condition through out-of-memory errors. This issue stems from the software's handling of specific network messages or data structures during the synchronization process or when processing incoming blocks and transactions. In these older versions, certain code paths fail to adequately limit memory allocation for untrusted inputs, allowing an attacker who is connected as a peer node in the Bitcoin P2P network to trigger excessive memory consumption on the victim's node. By sending specially crafted messages that exploit inefficient data structures or lack of bounds checking during parsing and validation routines, the malicious actor can force the application to allocate increasingly large amounts of RAM until the system runs out of available memory resources.
From a technical perspective, this flaw aligns with CWE-400, which describes conditions where an action is unconstrained regarding resource consumption, leading to denial of service. The vulnerability does not typically involve code execution or privilege escalation but rather focuses on destabilizing the node's availability by exhausting system memory. When the operating system detects that no more virtual memory can be allocated, it will terminate processes consuming excessive resources, often resulting in the Bitcoin Core daemon crashing unexpectedly. This crash disrupts the node's ability to relay transactions and blocks, effectively removing it from the network consensus process until manually restarted or automatically recovered by a service manager if configured with restart policies.
The operational impact of this vulnerability is significant for nodes that are publicly accessible on the internet. Since Bitcoin operates as a decentralized peer-to-peer network, any node accepting incoming connections is potentially exposed to such attacks. An attacker does not need authentication credentials; they only require network connectivity to send the malicious payload. For full nodes running in production environments or serving light clients via RPC interfaces, this vulnerability can cause intermittent downtime, increased latency for transaction propagation, and potential data inconsistency if the crash occurs during critical write operations. While the core protocol logic remains intact after recovery, repeated exploitation can degrade node performance over time due to fragmented memory states or corrupted temporary files left behind by abrupt terminations.
Mitigation strategies primarily involve upgrading to patched versions of Bitcoin Core where these resource limits have been enforced and data structures optimized to prevent unbounded growth. Administrators should ensure that their nodes are updated to version 29.5, 30.4, 31.2, or 32.1 or later as soon as possible. In the interim, network-level defenses such as firewalls can be configured to restrict incoming P2P connections from untrusted IP addresses or rate-limit new connection attempts to reduce exposure. Additionally, implementing monitoring tools that track memory usage of the Bitcoin Core process can provide early warning signs of resource exhaustion, allowing for proactive intervention before a full crash occurs. This vulnerability is categorized under ATT&CK technique T1498, which covers network denial of service via volumetric attacks or resource exhaustion through protocol abuse, highlighting the importance of maintaining up-to-date software to defend against such availability-focused threats in decentralized networks.