CVE-2025-65548

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.

CVSS 3.1

9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS

0.4% chance of exploitation in the next 30 days; higher than 35% of CVEs (scores of 2026-10-25)

CWE

CWE-1284

Published

2025-12-08

Modified

2026-10-18

Record from

the NVD, synced 2026-10-19

Affected

• cashu:nutshell

Packages (OSV)

References

• https://bitcointalk.org/index.php?topic=5564329
• https://delvingbitcoin.org/t/public-disclosure-denial-of-service-using-htlc-in-cashu/2090
• https://github.com/cashubtc/nuts/blob/main/07.md
• https://github.com/cashubtc/nuts/blob/main/14.md
• 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

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