critical9.1
CVE-2025-65849
Altcha Proof-of-Work obfuscation mode cryptanalytic break
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | altcha | >= 0.8.0, <= 2.2.4 | none recorded |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://altcha.org/docs/v2/obfuscation/
- https://github.com/altcha-org/altcha/blob/154f874cbcdd4e639783463130d13988a2bd1bdc/src/helpers.ts#L170-L194
- https://github.com/eternal-flame-AD/altcha-deobfs
- https://github.com/advisories/GHSA-mpmc-qchh-r9q8
- https://nvd.nist.gov/vuln/detail/CVE-2025-65849
- https://altcha.org/docs/v2/obfuscation