GitHub Advisoryadvisory · npm
GHSA-mpmc-qchh-r9q8 Altcha Proof-of-Work obfuscation mode cryptanalytic break
MEDIUM
Official page ↗
- Aliases
- CVE-2025-65849
- Ecosystem
- npm
- Packages
- altcha
- Severity
- Moderate
- CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P
- Weaknesses
- CWE-327
- Reviewed
- 2025-12-09
Affected packages
• npm altcha: >= 0.8.0, <= 2.2.4 (no fix yet)
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.
Related
Alias · CVE (1)
- CVE-2025-65849 A cryptanalytic break in Altcha Proof-of-Work obfuscation mode version 0.8.0 and later allows for remote visitors to recover the… vulnerability
Weakness · CWE (1)
- CWE-327 Use of a Broken or Risky Cryptographic Algorithm weakness
References
- https://nvd.nist.gov/vuln/detail/CVE-2025-65849 advisory
- https://altcha.org/docs/v2/obfuscation web
- https://github.com/altcha-org/altcha package
- https://github.com/altcha-org/altcha/blob/154f874cbcdd4e639783463130d13988a2bd1bdc/src/helpers.ts#L170-L194 web
- https://github.com/eternal-flame-AD/altcha-deobfs web