Is This vulnerability exploited in the wild?

No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

How severe is This vulnerability?

Medium severity, with a CVSS score of 4, published 23 October 2026.

Which products and versions are affected?

github.com/labstack/echo/v5 (Go) >= 5.0.0, < 5.4.1, SEMVER:introduced=5.0.0,fixed=5.4.1; Labstack Echo v5.0.0 through v5.4.0.

How is This vulnerability attacked?

It is attacked over the network.

Check whether you run github.com/labstack/echo/v5 (Go) or Labstack Echo at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Echo BodyDump middleware body limit bypass

Q: Is there a fix for This vulnerability?

Yes. github.com/labstack/echo/v5 (Go): upgrade to 5.4.1 or later. Until then: Disable BodyDump on affected routes, or ensure the BodyLimit overflow is detected during the initial capture by setting the BodyDump capture limit above the enforced body limit. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is This vulnerability attacked?

It is attacked over the network.

Q: Am I affected?

Check whether you run github.com/labstack/echo/v5 (Go) or Labstack Echo at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Severity: medium · CVSS 4 · Published 2026-10-23

Echo is a popular Go web framework used to build REST APIs and web services. The BodyDump middleware, used for request logging, was discarding size-limit violations on certain requests, allowing requests that exceeded configured body limits to be processed anyway. This is a conditional security policy bypass that could permit attackers to submit oversized payloads that handlers assume have been checked.

Technologies: github.com/labstack/echo/v5 (Go), Labstack Echo. Vendors: Go, Labstack.

Quick answers

Is This vulnerability exploited in the wild?: No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.
How severe is This vulnerability?: Medium severity, with a CVSS score of 4, published 23 October 2026.
Which products and versions are affected?: github.com/labstack/echo/v5 (Go) >= 5.0.0, < 5.4.1, SEMVER:introduced=5.0.0,fixed=5.4.1; Labstack Echo v5.0.0 through v5.4.0.
Is there a fix for This vulnerability?: Yes. github.com/labstack/echo/v5 (Go): upgrade to 5.4.1 or later. Until then: Disable BodyDump on affected routes, or ensure the BodyLimit overflow is detected during the initial capture by setting the BodyDump capture limit above the enforced body limit. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is This vulnerability attacked?: It is attacked over the network.
Am I affected?: Check whether you run github.com/labstack/echo/v5 (Go) or Labstack Echo at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

github.com/labstack/echo/v5 (Go): upgrade to 5.4.1 or later
```
go get github.com/labstack/echo/v5@v5.4.1
```

Disable BodyDump on affected routes, or ensure the BodyLimit overflow is detected during the initial capture by setting the BodyDump capture limit above the enforced body limit.

Technical details

Echo v5's BodyDump middleware captured a bounded prefix and silently drained the remaining body, then replaced it with only the prefix. When an unknown-length request (e.g. HTTP/1.1 chunked) exceeded an outer BodyLimit but had a BodyDump capture limit below that threshold, overflow errors during the drain were ignored and discarded. The handler received a truncated body but processed it as valid, bypassing the size policy. The vulnerability requires BodyDump to be active with a lower capture limit than the enforced BodyLimit, and affects only unknown-length requests; known-length requests are rejected before BodyDump runs.

Affected products

labstack Echo v5.0.0 through v5.4.0

Timeline

2026-10-23: disclosed

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.