Vulnerability · Published Dec 8, 2025 · Assigned by mitre
CVE-2025-65548
Critical 9.1
In plain English
A critical-severity security flaw in the cashu package (PyPI). Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)9.1Critical
Exploit odds (30 days)0.4%top 63.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | cashu | 0.18.0 | PYSEC-2025-89 |
Affected products (as reported)
Weakness: CWE-1284 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
References
- https://delvingbitcoin.org/t/public-disclosure-denial-of-service-using-htlc-in-cashu/2090
- https://github.com/cashubtc/nuts/blob/main/14.md
- https://github.com/cashubtc/nuts/blob/main/07.md
- https://preimage007.github.io/
- 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
- https://bitcointalk.org/index.php?topic=5564329