Inadequate Encryption Strength Affecting altcha package, versions >=0.8.0 <2.3.0
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-JS-ALTCHA-14236435
- published10 Dec 2025
- disclosed8 Dec 2025
- creditUnknown
Introduced: 8 Dec 2025
CVE-2025-65849 (opens in a new tab)How to fix?
Upgrade altcha to version 2.3.0 or higher.
Overview
altcha is a Privacy-first CAPTCHA widget, compliant with global regulations (GDPR/HIPAA/CCPA/LGDP/DPDPA/PIPL) and WCAG accessible. No tracking, self-verifying.
Affected versions of this package are vulnerable to Inadequate Encryption Strength in the Proof of Work obfuscation scheme. An attacker can recover sensitive nonce values by performing mathematical deduction in constant time.
Note:
Vendor mitigated this issue by moving the affected obfuscation plugin out of the main package.
However, the problematic cryptographic limitation is present in @altcha/plugins.
For more details, see vendor's Migration Guide to v2.3.0