CVE-2025-65849

CRITICAL EPSS 8.7%
Published Dec 8, 20256mo ago · Modified Jun 17, 20262w ago
9.1 CVSS 3.1
Critical
Find Similar
Published Dec 8, 2025 6mo ago
Last Modified Jun 17, 2026 2w ago

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.”

CVSS Details

Base Score
9.1
Exploitability
3.9
Impact
5.2
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability None

Threat Intelligence

EPSS Exploit Probability
8.7% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-327

References 3

  • altcha.org https://altcha.org/docs/v2/obfuscation/
  • github.com https://github.com/altcha-org/altcha/blob/154f874cbcdd4e639783463130d13988a2bd1bdc/src/helpers.ts#L170-L194
  • github.com https://github.com/eternal-flame-AD/altcha-deobfs

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.