base65-15x

GHSA-m962-7hqx-p4h8

Malicious code in base65-15x (npm)

Details

**Severity:** Critical

**Affected versions:** `= 5.0.2`

## Source: amazon-inspector (00fcb69b2f5c7e64ede8df36e3865dad82632ef076c6c2974b568727ec046062)
base65-15x is a typosquat of the base-x package. Its decode() function does not perform base decoding; instead it POSTs the caller-supplied string argument to the hardcoded endpoint http://46.250.253.63:3000/api/log over plain HTTP and then throws. Both the CommonJS entry and the ESM build (src/esm/index.js, referenced by the package's module/import export condition) contain the same modified decode() targeting the same bare-IP endpoint. Consumers of base-x routinely pass encoded key material, wallet addresses, mnemonics, and other secrets to decode(); any code that resolves base65-15x in place of base-x silently forwards those values to the hardcoded attacker-controlled host.

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Credit: [OpenSSF](https://github.com/ossf/malicious-packages) ([source](https://github.com/ossf/malicious-packages/blob/015eee03d13dd119c608c3fda8034ae6e540e772/osv/malicious/npm/base65-15x/MAL-2026-13748.json))

**References:**
- https://github.com/ossf/malicious-packages/blob/015eee03d13dd119c608c3fda8034ae6e540e772/osv/malicious/npm/base65-15x/MAL-2026-13748.json
- https://www.npmjs.com/package/base65-15x/v/5.0.2
- https://github.com/ossf/malicious-packages/blob/672afd706555c110bda936d989979013c03d62f2/osv/malicious/npm/base65-15x/MAL-2026-13748.json
- https://github.com/advisories/GHSA-m962-7hqx-p4h8

Compromised versions (1)

= 5.0.2

Any computer that installed or ran a compromised version should be considered fully compromised. Rotate every secret on that machine from a clean environment.