NUT-14 allows cashu tokens to be created with a preimage hash. However, nutshell (cashubtc/nuts) before 0.18.0 do not validate the size of preimage when the token is spent. The preimage is stored by the mint and attacker can exploit this vulnerability to fill the mint's db nd disk with arbitrary data.
Fix
Nothing published yet: no patch, vendor advisory or mitigation reference on NVD, no vendor advisory in the News for this CVE, not in CISA's KEV, no fixed package version. BaselineWatch does not guess at one.
Change history 1
- First seenCVSS 9.1 · cashuNVD modified 2026-10-18 14:10
Affected (CPE criteria) 1
cpe:2.3:a:cashu:nutshell:*:*:*:*:*:*:*:*
References 8
- https://bitcointalk.org/index.php?topic=5564329 Exploit, Issue Tracking
- https://delvingbitcoin.org/t/public-disclosure-denial-of-service-using-htlc-in-cashu/2090 Broken Link
- https://github.com/cashubtc/nuts/blob/main/07.md Exploit, Third Party Advisory
- https://github.com/cashubtc/nuts/blob/main/14.md Exploit, Third Party Advisory
- https://github.com/jamesob/delving-bitcoin-archive/blob/master/archive/rendered-topics/2025-11-November/2025-11-02-public-disclosure-denial-of-service-using-htlc-in-cashu-id2090.md Exploit, Third Party Advisory
- https://preimage007.github.io/ Product
- https://bitcointalk.org/index.php?topic=5564329 Exploit, Issue Tracking
- https://github.com/jamesob/delving-bitcoin-archive/blob/master/archive/rendered-topics/2025-11-November/2025-11-02-public-disclosure-denial-of-service-using-htlc-in-cashu-id2090.md Exploit, Third Party Advisory