Vulnerability in Cashu Nutshell
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (33.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000
Affected products
Weakness classification (CWE)
References
- delvingbitcoin.org/t/public-disclosure-denial-of-service-using-htlc-in-cashu/20… (Broken Link)
- github.com/cashubtc/nuts/blob/main/14.md (Exploit, Third Party Advisory)
- github.com/cashubtc/nuts/blob/main/07.md (Exploit, Third Party Advisory)
- preimage007.github.io/ (Product)
- github.com/jamesob/delving-bitcoin-archive/blob/master/archive/rendered-topics/… (Exploit, Third Party Advisory)
- bitcointalk.org/index.php (Exploit, Issue Tracking)
Frequently asked questions
- What is CVE-2025-65548?
- CVE-2025-65548 is a critical-severity vulnerability in Cashu Nutshell, classified under Improper Validation of Specified Quantity in Input. CVSS score: 9.1/10. Published 2025-12-08.
- How severe is CVE-2025-65548?
- Critical severity. CVSS v3 base score is 9.1 out of 10.