CVE-2025-65849

CRITICAL

Altcha Proof-of-Work >=0.8.0 - Info Disclosure

Title source: llm
STIX 2.1

Description

A cryptanalytic break in Altcha Proof-of-Work obfuscation mode version 0.8.0 and later allows for remote visitors to recover the Proof-of-Work nonce in constant time via mathematical deduction. NOTE: this is disputed by the Supplier because the product's objective is "to discourage automated scraping / bots, not guarantee resistance to determined attackers." The documentation states “the goal is not to provide a secure cryptographic algorithm but to use a proof-of-work mechanism that allows any capable device to decrypt the hidden data.”

Scores

CVSS v3 9.1
EPSS 0.0002
EPSS Percentile 6.1%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact total

Details

CWE
CWE-327
Status published
Products (1)
npm/altcha 0.8.0npm
Published Dec 08, 2025
Tracked Since Feb 18, 2026