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Fencer Intel
critical 9.1

CVE-2025-65548 json

NUT-14 allows cashu tokens to be created with a preimage hash.

published 11mo ago modified 22d ago also PYSEC-2025-89 , EUVD-2025-201796

cvss
9.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 39%
public exploits
0
none known

Summary

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.

Patch / fix

  • pypi cashu 0.18.0
  • cashu nutshell 0.18.0

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
total
Assessed
11mo ago

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com 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 referenced PoC, tagged "exploit" by a source, unverified
  • bitcointalk.org https://bitcointalk.org/index.php?topic=5564329 referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/cashubtc/nuts/blob/main/14.md referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/cashubtc/nuts/blob/main/07.md referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CNA 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
OSV 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected packages

ecosystem package affected fixed in
pypi cashu
<0.18.0
0.18.0

Classification

Weakness
  • CWE-1284 Improper Validation of Specified Quantity in Input

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.