# CVE-2023-39910 — Libbitcoin Explorer

> As of 2026-07-10, CVE-2023-39910 is a HIGH-severity vulnerability in Libbitcoin Explorer, CVSS v3.1 7.5, EPSS 1.8% (77.9th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2023-39910, most recently “'Ill Bloom' Weak-Randomness Vulnerability in Legacy Crypto Wallets Actively Exploited to Drain $3.1M+”.

**Last updated:** 2026-07-10

## What is CVE-2023-39910?

The cryptocurrency wallet entropy seeding mechanism used in Libbitcoin Explorer 3.0.0 through 3.6.0 is weak, aka the Milk Sad issue. The use of an mt19937 Mersenne Twister PRNG restricts the internal entropy to 32 bits regardless of settings. This allows remote attackers to recover any wallet private keys generated from "bx seed" entropy output and steal funds. (Affected users need to move funds to a secure new cryptocurrency wallet.) NOTE: the vendor's position is that there was sufficient documentation advising against "bx seed" but others disagree. NOTE: this was exploited in the wild in June and July 2023.

The record classifies CVE-2023-39910 under weakness class [CWE-338](https://cwe.mitre.org/data/definitions/338.html). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 1192 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.5 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **EPSS (FIRST):** 1.8% probability of exploitation in the next 30 days, higher than 77.9% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 8.9/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2023-08-09

## Is CVE-2023-39910 being exploited?

Weaponised exploit code for CVE-2023-39910 is publicly available. 4 public proof-of-concept repositories are tracked for this identifier. It currently carries a trending score of 32 in the Threadlinqs vulnerability feed.

- [z1ph1us/MilkSad-Mnemonic-Generator](https://github.com/z1ph1us/MilkSad-Mnemonic-Generator) (github)
- [demining/RAMnesia-Attack](https://github.com/demining/RAMnesia-Attack) (github)
- [Xaxis/bitcoin-security](https://github.com/Xaxis/bitcoin-security) (github)
- [trickest/cve](https://github.com/trickest/cve/blob/main/2023/CVE-2023-39910.md) (trickest)

## Affected products and versions

- **Libbitcoin**: Explorer

## How to fix CVE-2023-39910

No vendor patch reference has been recorded for CVE-2023-39910 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2023-39910

1 tracked threat in the Threadlinqs corpus references CVE-2023-39910, either in the campaign’s CVE list or as an indicator on the campaign record.

- ['Ill Bloom' Weak-Randomness Vulnerability in Legacy Crypto Wallets Actively Exploited to Drain $3.1M+](https://intel.threadlinqs.com/threat/TL-2026-1170) — CRITICAL · 2026-07-10

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories, public proof-of-concept repositories. This product uses the NVD API but is not endorsed or certified by the NVD.

**Other references**

- [github.com](https://github.com/libbitcoin/libbitcoin-explorer/blob/20eba4db9a8a3476949d6fd08a589abda7fde3e3/src/commands/seed.cpp#L44)
- [github.com (utility)](https://github.com/libbitcoin/libbitcoin-explorer/blob/20eba4db9a8a3476949d6fd08a589abda7fde3e3/src/utility.cpp#L78)
- [github.com (pseudo random)](https://github.com/libbitcoin/libbitcoin-system/blob/a1b777fc51d9c04e0c7a1dec5cc746b82a6afe64/src/crypto/pseudo_random.cpp#L66C12-L78)
- [milksad.info](https://milksad.info/disclosure.html)
- [news.ycombinator.com](https://news.ycombinator.com/item?id=37054862)

_Showing 5 of 6 recorded references._

Canonical: https://intel.threadlinqs.com/cve/CVE-2023-39910
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