Description
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.
Affected products
cashu: nutshell
References8
- bitcointalk.org/index.php?topic=5564329 ExploitIssue Tracking
- github.com/cashubtc/nuts/blob/main/07.md ExploitThird Party Advisory
- github.com/cashubtc/nuts/blob/main/14.md ExploitThird Party Advisory
- github.com/jamesob/delving-bitcoin-archive/blob/master/archive/… ExploitThird Party Advisory
- bitcointalk.org/index.php?topic=5564329 ExploitIssue Tracking
- github.com/jamesob/delving-bitcoin-archive/blob/master/archive/… ExploitThird Party Advisory
- delvingbitcoin.org/t/public-disclosure-denial-of-service-using-… Broken Link
- preimage007.github.io/ Product
Metrics
- CVSS 3.1
-
9.1
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - EPSS — exploit probability
- 0% percentile: 39 · as of 11 November 2026
- CWE
- CWE-1284
Could this be exploited in your environment?
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