6.3

CVE-2026-118681: go-chi chi before 5.5.0 Authentication Bypass via SupressNotFound Middleware

Deferred
AliasesDEBIAN-CVE-2026-118681UBUNTU-CVE-2026-118681
Published 28-10-2026Last modified 03-11-2026

Vulnerability summary

CVE-2026-118681 is a medium (CVSS 6.3) vulnerability in go-chi chi. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 15.6% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 6.3, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
6.3/10
010
Medium · v4.0 (CVE.org)
EPSS score
0.24%
0%100%
Low · Change unavailable
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 28-10-2026
    PublishedVulnerability first disclosed.
  2. 03-11-2026
    Last modifiedVulnerability information updated.

Description

go-chi chi before 5.5.0 contains an authentication bypass in middleware.SupressNotFound, which calls Match with the live routing context and leaves a mounted router's parameter and child suffix in place for dispatch against the outer router. Unauthenticated attackers can request a mounted path whose suffix matches an outer public route, skipping the mounted authentication middleware and retrieving tenant-scoped data when that outer handler trusts the retained mount parameter.

CVSS metrics

7 scores · 4 sources · 2 versions

EPSS trend

Probability

0.24%

Chance of exploitation in the next 30 days

Percentile

16%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

29-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Debian1 product
  • golang-github-go-chi-chiAll versions (No fix recorded)
Go-chi1 product
Ubuntu1 product
  • golang-github-go-chi-chiAll versions (No fix recorded)

3 vendors · 3 products

References

5 links