Bitcoin Optech newsletter #411 is here: - describes the responsible disclosure of a denial-of-service vulnerability that affected older versions of LND - summarizes popular Q&A from Stack Exchange - Optech Newsletter #411 Podcast https://bitcoinops.org/en/newsletters/2026/06/26/ Nishant Bansal posted to Delving Bitcoin disclosing a denial-of-service vulnerability he discovered through state-machine fuzzing of LND’s gossip handling... https://bitcoinops.org/en/newsletters/2026/06/26/#lnd-zero-timestamp-gossip-dos-disclosure Selected Q&A from Bitcoin Stack Exchange - Is it a bug that OP_IF is part of the tapscript opcodes? - Why would forbidding OP_IF in tapscript be a problem? - Does a softfork always succeed? - How to set up Bitcoin Core to mine a valid block after the BIP110 activation in August 2026? - Are BIP110 blocks on a branch with lower difficulty valid? - What is the story behind Bitcoin test networks? - Why was -datacarriersize redefined in 2022, and why was the 2023 proposal to expand it not merged? - Are chains of 26 unconfirmed transactions prohibited by the wallet in Bitcoin Core 31.0? - Are there changes in Bitcoin Core 29.0 that affect memory usage? - What is Bitcoin Core’s release schedule? https://bitcoinops.org/en/newsletters/2026/06/26/#selected-qa-from-bitcoin-stack-exchange Bitcoin Optech will host an audio recap discussion of this newsletter streaming live on X/Twitter Tuesday at 16:30 UTC.

rkrux, Roland Bewick, and Steven Roose joined Optech to discuss Newsletter #410: - Discussion of removing RBF signaling from wallet transactions - Changes to services and client software including Sparrow, Alby, JoinMarket NG, Bark, Arké, Noah - And more You can listen on our website: https://bitcoinops.org/en/podcast/2026/06/23/ Spotify: https://open.spotify.com/episode/47quyifrpjUmeqHoZcm308 Apple Podcasts: https://podcasts.apple.com/us/podcast/bitcoin-optech-newsletter-410-recap/id1674626983?i=1000773932392

Bitcoin Optech newsletter #410 is here: - summarizes a discussion about wallets removing opt-in replace-by-fee signaling from the transactions they create - summarizes changes to services/client software - Optech Newsletter #410 Podcast https://bitcoinops.org/en/newsletters/2026/06/19/ rkrux posted to the Bitcoin-Dev mailing list proposing that wallets stop signaling opt-in RBF in the transactions they create... https://bitcoinops.org/en/newsletters/2026/06/19/#discussion-of-removing-rbf-signaling-from-wallet-transactions Changes to services and client software: - Sparrow Wallet 2.5.0 adds silent payments receiving - Bark live on Bitcoin mainnet - Arké Ark wallet announced - Noah Ark wallet announced - Alby Hub v1.23.0 released - JoinMarket NG 0.32.0 released https://bitcoinops.org/en/newsletters/2026/06/19/#changes-to-services-and-client-software Bitcoin Optech will host an audio recap discussion of this newsletter streaming live on X/Twitter Tuesday at 16:30 UTC.

Vasil Dimov joined Optech to discuss Newsletter #409: - Draft BIP for testnet5 - The bug in private transaction broadcast - And more You can listen on our website: https://bitcoinops.org/en/podcast/2026/06/16/ Spotify: https://open.spotify.com/episode/1sOOad7jS2bJan4pIQXjlb Apple Podcasts: https://podcasts.apple.com/us/podcast/bitcoin-optech-newsletter-409-recap/id1674626983?i=1000773137157

Bitcoin Optech newsletter #409 is here: - describes a draft BIP to replace the testnet4 test network with a successor - Optech Newsletter #409 Podcast https://bitcoinops.org/en/newsletters/2026/06/12/ Pol Espinasa posted to the Bitcoin-Dev mailing list a draft BIP, co-authored with Fabian Jahr, to replace testnet4 with testnet5... https://bitcoinops.org/en/newsletters/2026/06/12/#draft-bip-for-testnet5 Bitcoin Optech will host an audio recap discussion of this newsletter streaming live on X/Twitter Tuesday at 16:30 UTC.

Pyth and Ademan joined Optech to discuss Newsletter #408: - Post-quantum BIP324 - QR signing payloads for miniscript wallets - CTV-only vault proof of concept - Post-quantum Lightning discussion - Quantum attack game theory - BIP54 64-byte transactions and potential legitimate uses - And more You can listen on our website: https://bitcoinops.org/en/podcast/2026/06/09/ Spotify: https://open.spotify.com/episode/67RadnujhmE0AIZbfBDjJ0 Apple Podcasts: https://podcasts.apple.com/us/podcast/bitcoin-optech-newsletter-408-recap/id1674626983?i=1000772045814

Bitcoin Optech newsletter #408 is here: - summarizes ideas to make BIP324 transport encryption quantum secure - describes a proposal to standardize QR-based signing payloads for miniscript wallets - links to a CTV-only vault proof of concept - outlines points from a post-quantum Lightning thread - summarizes a quantum attack game theory post - points to discussion of 64-byte transactions and potential uses - Optech Newsletter #408 Podcast https://bitcoinops.org/en/newsletters/2026/06/05/ Olaoluwa Osuntokun posted to the Bitcoin-Dev mailing list his thoughts on possible upgrades needed to make BIP324 quantum secure... https://bitcoinops.org/en/newsletters/2026/06/05/#a-post-quantum-path-for-bip324 Pyth posted to Delving Bitcoin a proposal to standardize the data payloads exchanged between wallet coordinators and air-gapped signing devices over QR codes when using miniscript-based spending policies... https://bitcoinops.org/en/newsletters/2026/06/05/#discussion-of-qr-signing-payloads-for-miniscript-wallets Ademan announced on Delving Bitcoin the 0.1.0 release of his CTV (BIP119) vault project called MCCV (More Complicated CTV Vault)... https://bitcoinops.org/en/newsletters/2026/06/05/#ctv-only-vault-proof-of-concept Olaoluwa Osuntokun (roasbeef) posted to Delving Bitcoin a breakdown of how a post-quantum Lightning Network might look... https://bitcoinops.org/en/newsletters/2026/06/05/#post-quantum-lightning-discussion Jameson Lopp posted to Delving Bitcoin his blog post about the game theory of a quantum attack... https://bitcoinops.org/en/newsletters/2026/06/05/#quantum-attack-game-theory Jeremy Rubin wrote to the Bitcoin-Dev mailing list about potential legitimate uses for 64-byte witness-stripped transactions... https://bitcoinops.org/en/newsletters/2026/06/05/#bip54-64-byte-transactions-and-potential-legitimate-uses Bitcoin Optech will host an audio recap discussion of this newsletter streaming live on X/Twitter Tuesday at 16:30 UTC.

Chandra Pratap joined Optech to discuss Newsletter #407: - Core Lightning assertion DoS disclosure - Bitcoin Core developer meeting transcripts - And more You can listen on our website: https://bitcoinops.org/en/podcast/2026/06/02/ Spotify: https://open.spotify.com/episode/3FXtYki8QCcpj3fQQP12y6 Apple: https://podcasts.apple.com/us/podcast/bitcoin-optech-newsletter-407-recap/id1674626983?i=1000770819043