GHSA-h7wr-284f-5qvc

Echo: Decompress permits unbounded gzip expansion in v4

Risk score: 59/100
CVSS: 8.2 v4.0
Published: 23 Oct 2026

Open in the live forecast Today's forecast

What to know

What it is: Echo v4's opt-in Decompress middleware exposed a gzip-decoded request stream without limiting its expanded size. A small compressed request could therefore produce a very large decoded body. Handlers that read or bind that body could consume excessive memory or CPU, and repeated or concurrent requests could cause deni…
Affected: github.com/labstack/echo/v4 (go) >= 4.0.0, < 4.16.1
Fix: Upgrade github.com/labstack/echo/v4 to 4.16.1 or later.
Exploitation: No known exploitation

Why it is Yellow

CVSS 8.2 high
Remotely exploitable without logging in
On your watchlist: Go

Affected packages

Package	Ecosystem	Vulnerable	Fixed in
github.com/labstack/echo/v4	go	>= 4.0.0, < 4.16.1	4.16.1

References

Original description

## Impact Echo v4's opt-in Decompress middleware exposed a gzip-decoded request stream without limiting its expanded size. A small compressed request could therefore produce a very large decoded body. Handlers that read or bind that body could consume excessive memory or CPU, and repeated or concurrent requests could cause denial of service. The middleware is not enabled by default. A limit on the compressed request size alone does not bound the decompressed size. Applications that already apply an effective body limit after decompression have reduced exposure. ## Affected versions and patch Echo v4 versions through v4.16.0 are affected. Upgrade to [v4.16.1](https://github.com/labstack/echo/releases/tag/v4.16.1). The patch adds `DecompressConfig.MaxDecompressedSize`, defaulting to 100 MiB when zero. A value of `-1` explicitly disables the limit. Reading beyond the cap returns `ErrStatusRequestEntityTooLarge` (HTTP 413), including through JSON and XML binding. Bodies exactly at the configured limit remain valid. Streaming enforcement requires callers to handle body-read errors. [Fix commit](https://github.com/labstack/echo/commit/3fb0ba7e17645bb65611e2a08875d0a2f65c421f). ## Workarounds Disable gzip request decompression on exposed routes, or place BodyLimit after Decompress so the application limit applies to decoded bytes. Apply suitable request deadlines and concurrency limits as well. ## Credits Reported by @q490107865. The exact-limit behavior incorporates @Shubham-Padkonde's work in [#3136](https://github.com/labstack/echo/pull/3136).

Last activity 23 Oct 2026. Patch Forecast updates every hour.