# Cardano Incident Update — What Happened & How We Responded On **Friday, 21 November 2025 at around 08:00 UTC** , the Cardano network experienced a complex chain partition triggered by a malformed delegation transaction exploiting a dormant deserialization bug in certain node versions. This affected many services across the ecosystem — including Danogo. As always, we want to communicate clearly and transparently about what happened on our side. *** ### **How this impacted Danogo** Danogo was running **Cardano node version 10.4.1**, one of the versions affected by the issue: #### **1. Our node could not consume new blocks** Because of the chain partition, nodes on v10.4.1 became stuck behind the healthy chain.\ This meant Danogo’s backend couldn't follow the main chain correctly. #### **2. Ogmios could not receive fresh block data** Our Ogmios service depends on the node to stream the latest blocks.\ When the node stalled, Ogmios stopped receiving updates. #### **3. Transaction builder received outdated UTXOs** Without fresh block data, our transaction builder could not access correct UTXO information.\ **Result:**\ Users could not build or submit new transactions during the incident window. Throughout this time, **user funds remained completely safe**, and no on-chain Danogo positions were affected. *** ### **Our Response** As soon as updated node versions were announced from Intersect (), we acted immediately: #### **✔ Upgraded to Cardano node 10.5.2** This is the patched version aligned with the healthy chain. #### **✔ Full resynchronization of the chain** Our node required \~9 hours to fully resync to the canonical chain, restoring normal service. #### **✔ System checks & validation** We validated UTXO correctness, Ogmios data freshness, and transaction-building flows before reopening the platform. Danogo is now **fully operational**. *** ### **Key Takeaways** * Danogo was affected *only* because the older node version (10.4.1) stalled during the chain split. * No funds were at risk, and all on-chain logic stayed intact. * The downtime was a direct result of the Cardano node deserialization issue, not a Danogo smart contract or backend failure. * Upgrading to the patched version restored full service. *** ### **Moving Forward** We are taking additional steps to strengthen resilience: * Faster node upgrade cadence * Additional node health monitoring * More redundancy in block-sync infrastructure * Automatic UTXO validation fallback paths for extreme consensus events If you submitted a transaction during the incident window and it did not appear on-chain, you may need to **resubmit** it. Our team can assist if needed. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.dano.finance/news/cardano-incident-update-what-happened-and-how-we-responded.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.