Answer in brief
CVE-2026-118656 records a Medium severity (CVSS 6.1) vulnerability in Echo: Open Redirect via Control-Character Prefix Defeating sanitizeURI. The current sources do not mark it as known exploited. The current feed maps labstack/echo (generic), github.com/labstack/echo/v4 (go), github.com/labstack/echo/v5 (go). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 6.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps labstack/echo (generic), github.com/labstack/echo/v4 (go), github.com/labstack/echo/v5 (go). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| labstack/echogeneric | >=5.0.0 <5.4.0 || <4.16.0 | 4.16.0, 5.4.0 |
| github.com/labstack/echo/v4go | <4.16.0 | 4.16.0 |
| github.com/labstack/echo/v5go | <5.4.0 | 5.4.0 |
Published upstream
Oct 28, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 28, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 28, 2026
Echo is a Go web framework. Prior to 4.16.0 and 5.4.0, sanitizeURI checks only the first two bytes of a redirect target before deciding whether it begins with an absolute-path separator pair. When AddTrailingSlash or RemoveTrailingSlash is configured with a redirect status, a slash, TAB, separator path form can evade the guard, be emitted in the Location header, and be normalized by a browser into an attacker-controlled host. This issue is fixed in 4.16.0 and 5.4.0.
Quoted source text, attributed separately from HOL analysis.