AI scan reveals Bitcoin Core flaws crashing nodes
An automated AI scan has unearthed a trio of security flaws in Bitcoin Core, the network’s primary software, including one that could allow a remote attacker to crash nodes running on Windows and macOS. The discovery prompted developers to release immediate patches and marks the first major disclosure under a new, accelerated security policy designed for the age of AI-driven bug hunting.
Bitcoin Core developers disclosed the vulnerabilities on October 28, 2026, after fixes were shipped the day before. The most significant flaw, rated as medium severity, allows a malicious actor to flood a node with data until it exhausts its memory and shuts down, potentially disrupting parts of the network.
A closer look at the Bitcoin Core flaws
This incident underscores a paradigm shift in open-source security, where the speed of AI analysis is forcing projects to rethink long-standing disclosure practices.
The vulnerabilities were first identified by Spiral’s Project Loupe, which uses large language models (LLMs) to automatically scan code for potential weaknesses. After human validation by developer Gregory Sanders, the findings were reported to the Bitcoin Core team, underscoring the constant need for vigilance within the Bitcoin development ecosystem.
The most critical of the three allows an attacker to use specially marked TCP network traffic to bypass data queue limits, causing an unstoppable memory growth that crashes the node. This specific attack vector affects nodes on Windows, macOS, and BSD systems, but not Linux, which uses a different method for monitoring network connections.
A second medium-severity bug also leads to memory exhaustion, but through a different mechanism. An attacker’s node can pretend to use an outdated version of the Bitcoin protocol that lacks modern timeout checks. This allows the malicious peer to stall communications, forcing the victim’s node to queue up transaction announcements indefinitely.
This can cause memory usage to climb by up to 2 megabytes per hour for each inbound connection and 5 megabytes per hour for each outbound one.
The third vulnerability, classified as low severity, involves the files a node uses to handle blockchain reorganizations. A miner could, in theory, create a series of blocks that cause these “undo” files to grow beyond their size limits, potentially corrupting data or crashing the node.
While developers consider this attack impractical on modern 64-bit machines, noting it would require immense resources, it remains a threat to older 32-bit systems or nodes storing block data on older FAT32 filesystems. For these systems, a simple restart is not enough; a full rebuild of the blockchain index with patched software is required.
A new security policy for a new era
The rapid disclosure of these bugs is a direct result of a policy change Bitcoin Core adopted on October 22, 2026. Previously, developers often kept medium- and high-severity vulnerabilities under an embargo for up to a year.
This gave the thousands of individuals and businesses running nodes ample time to upgrade before details of the exploit became public. However, the rise of AI has rendered that model obsolete.
The new policy acknowledges that if an AI can find a bug with a simple prompt, so can a malicious actor. The focus has now shifted to rapid patching and transparency for these “easily discoverable” flaws. Fixes are now backported to all supported versions and released concurrently with a public security advisory.
This approach aims to close the window of opportunity for attackers who may be using the same AI tools to find and exploit weaknesses.
This strategic shift highlights a fundamental tension in cybersecurity. On one hand, silent patching gives defenders a head start. On the other, it can leave the network exposed if attackers discover the bug independently.
By moving to immediate public disclosure for AI-found bugs, Bitcoin Core is betting that transparency and speed are now the more effective defense. Meanwhile, the release notes stated that three more medium- and high-severity bugs, fixed in version 30.0, are expected to be disclosed in two weeks, signaling this new rhythm for vulnerability handling.
A pattern of AI-driven security events
This incident is not an isolated event but rather the latest in a series of security challenges posed by AI in the crypto space. In late July 2026, a volunteer group known as the Bitcoin Red Team demonstrated the power of these tools by running AI models across 390 Bitcoin-related code repositories.
In just over 27 hours, their scan generated 4,962 findings, including 85 rated as critical and 635 as high-severity.
The real-world consequences of such discoveries have already been felt. In late July, a flaw in the BTCPay Server, privately reported by the Red Team, was exploited on live servers, draining funds from merchants’ Lightning Network nodes.
Shortly after, in August 2026, developers for Core Lightning urged operators to upgrade or disconnect their nodes after AI-generated reports of a vulnerability proved accurate. These events have shown that the entire Bitcoin development ecosystem is a target.
Even more dramatic was the July 30, 2026, exploit of a Coldcard hardware wallet, where an attacker drained 594 BTC, worth approximately $114 million at the time, in just 25 minutes.
While not directly attributed to AI in the same way, it demonstrated the speed and scale of modern attacks, reinforcing the need for proactive and rapid security responses across the industry.
The decision by Bitcoin Core to not assign formal CVE identifiers to these latest three vulnerabilities marks a notable, though unexplained, departure from past practices.
What node operators must do now
For individuals and businesses running Bitcoin nodes, the guidance is clear and urgent: upgrade your software immediately. The fixes for these vulnerabilities are included in Bitcoin Core versions 29.5, 30.4, 31.2, and 32.1. Developers have stressed the importance of shutting down the existing Bitcoin Core software completely before installing the updated version to ensure the patch is applied correctly.
This update cycle also serves as a critical reminder for operators running older software. Bitcoin Core versions 29.x and earlier have officially reached their end-of-life. They will no longer receive security updates or bug fixes, leaving them permanently exposed to these and any future vulnerabilities.
Continuing to run end-of-life software poses a direct risk to the operator and a potential threat to the stability of the wider network. The underlying security of the base layer remains paramount as the digital asset space continues to evolve with new financial products.
The emergence of AI as a potent tool for code analysis represents a double-edged sword. While it empowers developers and security researchers to find and fix bugs faster than ever before, it also equips attackers with the same capabilities.
The ongoing disclosures from Bitcoin Core signal a new front in the cybersecurity arms race, one where proactive defense and rapid response are the keys to maintaining the integrity of the world’s oldest and largest cryptocurrency network.