Echo v4 Decompress 中介軟體未限制 gzip 解壓大小，易導致 DoS 攻擊（CVE-2026-118261）
CVE-2026-118261 - Echo: Decompress permits unbounded gzip expansion in v4
Echo v4 的 Decompress 中介軟體在 4.0.0 至 4.16.1 版本中未限制 gzip 解壓後的大小，可能導致記憶體耗盡或 CPU 過載，進而造成拒絕服務。
此漏洞揭示未限制 gzip 解壓大小所帶來的 DoS 風險，提醒開發者在使用 Echo Decompress 中介軟體時必須加上輸入大小限制或停用功能。
Echo is a Go web framework. From 4.0.0 until 4.16.1, Echo v4's opt-in Decompress middleware exposes a gzip-decoded request stream without limiting its expanded size. A small compressed request can expand into a very large body when a handler reads or binds it, consuming excessive memory or CPU and allowing repeated or concurrent requests to cause denial of service. The middleware is not enabled by default, and limiting only the compressed request size does not bound the decoded size. This issue is fixed in 4.16.1.
Impact
Affected Products
The following products are affected by CVE-2026-118261
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
| ID | Vendor | Product | Action |
|---|---|---|---|
| 1 | Labstack | echo |
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | HIGH | [email protected] |
Update Echo v4 to version 4.16.1 or later to fix the decompression vulnerability.
- Update Echo v4 to version 4.16.1.
- Review middleware configuration for decompression.
- Apply input size limits to decompressed data.
- Consider disabling decompression if unused.
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The following table lists the changes that have been made to the
CVE-2026-118261 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
十月. 28, 2026
Action Type Old Value New Value Added Description Echo is a Go web framework. From 4.0.0 until 4.16.1, Echo v4's opt-in Decompress middleware exposes a gzip-decoded request stream without limiting its expanded size. A small compressed request can expand into a very large body when a handler reads or binds it, consuming excessive memory or CPU and allowing repeated or concurrent requests to cause denial of service. The middleware is not enabled by default, and limiting only the compressed request size does not bound the decoded size. This issue is fixed in 4.16.1. Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-400 Added CWE CWE-409 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/118xxx/CVE-2026-118261.json">CVE-2026-118261</a> Added Reference https://github.com/labstack/echo/commit/3fb0ba7e17645bb65611e2a08875d0a2f65c421f Added Reference https://github.com/labstack/echo/releases/tag/v4.16.1 Added Reference https://github.com/labstack/echo/security/advisories/GHSA-h7wr-284f-5qvc
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.