A cryptanalytic break in Altcha Proof-of-Work obfuscation mode version 0.8.0 and later…
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and GitHub. Impact type from CWE-327.
Summary
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.”
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
| — | altcha (npm) | 0.8.0 – 2.2.4 | — | No fix listed | GHSA-mpmc-qchh-r9q8 |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- altcha (npm) Vendor— Affected 0.8.0 – 2.2.4 Fixed in — No fix listed GHSA-mpmc-qchh-r9q8
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2025-65849
- 2026-10-03 Alias added: GHSA-mpmc-qchh-r9q8
References
Sources
- CVE-2025-65849 · CVE Program
- CVE-2025-65849 · NVD
- FIRST EPSS
- GHSA-mpmc-qchh-r9q8 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences