GHSA-H7WR-284F-5QVC
Vulnerability from github – Published: 2026-10-23 20:49 – Updated: 2026-10-28 18:58Impact
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.
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.
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.
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/labstack/echo/v4"
},
"ranges": [
{
"events": [
{
"introduced": "4.0.0"
},
{
"fixed": "4.16.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-118261"
],
"database_specific": {
"cwe_ids": [
"CWE-400",
"CWE-409"
],
"github_reviewed": true,
"github_reviewed_at": "2026-10-23T20:49:49Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "## Impact\n\nEcho v4\u0027s 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.\n\nThe 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.\n\n## Affected versions and patch\n\nEcho v4 versions through v4.16.0 are affected. Upgrade to [v4.16.1](https://github.com/labstack/echo/releases/tag/v4.16.1).\n\nThe 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.\n\n[Fix commit](https://github.com/labstack/echo/commit/3fb0ba7e17645bb65611e2a08875d0a2f65c421f).\n\n## Workarounds\n\nDisable 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.\n\n## Credits\n\nReported by @q490107865. The exact-limit behavior incorporates @Shubham-Padkonde\u0027s work in [#3136](https://github.com/labstack/echo/pull/3136).",
"id": "GHSA-h7wr-284f-5qvc",
"modified": "2026-10-28T18:58:50Z",
"published": "2026-10-23T20:49:49Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/labstack/echo/security/advisories/GHSA-h7wr-284f-5qvc"
},
{
"type": "WEB",
"url": "https://github.com/labstack/echo/pull/3136"
},
{
"type": "WEB",
"url": "https://github.com/labstack/echo/commit/3fb0ba7e17645bb65611e2a08875d0a2f65c421f"
},
{
"type": "PACKAGE",
"url": "https://github.com/labstack/echo"
},
{
"type": "WEB",
"url": "https://github.com/labstack/echo/releases/tag/v4.16.1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Echo: Decompress permits unbounded gzip expansion in v4"
}
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
Loading timeline…
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.