Bitcoin Blockchain at Risk? Inscription Vulnerability Spams Transactions

In a recent revelation, the well-known Bitcoin Core developer Luke Dashjr brought attention to a significant vulnerability within the Bitcoin Core, aptly named Inscription. This discovery has caused a stir in the cryptocurrency community, revealing a potential weakness in the blockchain’s defense against spam.

Breaking Down the Issue

Dashjr explains that since 2013, Bitcoin Core users have had the ability to set limits on extra data in transactions using the -datacarriersize setting. However, the clever Inscription method has found a way to get around this limit by disguising its data as program code.

This crafty maneuver effectively sidesteps the intended restrictions, resulting in what Dashjr calls “spamming the blockchain.” While this problem was addressed in Bitcoin Knots v25.1, Bitcoin Core remains vulnerable in its upcoming v26 release. The community is hopeful for a fix before the expected v27 release next year.

Discussions within the cryptocurrency community are buzzing with various concerns and questions. One significant inquiry revolves around the economic incentives for miners dealing with inscription transactions. Dashjr emphasizes Bitcoin’s assumption that most miners operate honestly. He also notes that blocks filtered for spam often come with higher fees for reasons not yet understood.

Further questions probe into the implications of fixing this vulnerability. A crucial point of discussion is whether addressing the bug would bring an end to ordinals and brc-20 tokens. Dashjr confirms that fixing this issue would indeed put a stop to these practices.


Another community member seeks clarification on how this vulnerability directly affects regular Bitcoin holders. Dashjr clarifies that while the primary concern is technical, related to blockchain efficiency and integrity, there could be indirect effects on security and value.

What Next?

The conversation extends to practical steps users can take in response to this issue. For Bitcoin Knots users, Dashjr recommends setting the datacarriersize to zero to stop the relay of Inscription data. He adds a caution that the “Bitcoin Core policy” mode should not be enabled for the correct handling of Inscriptions.

As we approach the Bitcoin Core v26 release, all eyes are watching for the resolution that could shape the future of Bitcoin transactions.