6.9

CVE-2026-72817: go-chi chi 0.9.0 before 5.3.0 IP Spoofing via X-Forwarded-For

Deferred
AliasesUBUNTU-CVE-2026-72817DEBIAN-CVE-2026-72817GHSA-9g5q-2w5x-hmxf
Published 14-08-2026Last modified 08-10-2026

Vulnerability summary

CVE-2026-72817 is a medium (CVSS 6.9) vulnerability in go-chi chi. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 15.4% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 6.9, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
6.9/10
010
Medium · v4.0 (CVE.org)
EPSS score
0.24%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 10 · Related 8
OPENSUSE-SU-2026:11574-1OPENSUSE-SU-2026:11810-1OPENSUSE-SU-2026:21645-1OPENSUSE-SU-2026:21653-1OPENSUSE-SU-2026:21670-1OPENSUSE-SU-2026:21793-1

Timeline

  1. 14-08-2026
    PublishedVulnerability first disclosed.
  2. 08-10-2026
    Last modifiedVulnerability information updated.

Description

go-chi/chi versions 0.9.0 before 5.3.0 contains an IP spoofing vulnerability in the RealIP middleware, which resolves the request source IP (Request.RemoteAddr) using the first IP in the X-Forwarded-For header without validating trusted proxies. A malicious client can prepend a forged IP as the first value of the X-Forwarded-For header to spoof the request source IP, potentially bypassing access controls or falsifying request logs.

CVSS metrics

8 scores · 5 sources · 2 versions

EPSS trend

Probability

0.24%

Chance of exploitation in the next 30 days

Percentile

15%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.24% on 04-10-2026

04-10-202603-11-2026

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.

Github.com/go-chi/chi2 products
  • middleware≥ 0.9.0, ≤ 1.5.5
  • v5< 5.3.0
Opensuse2 products
  • trivy&distro=openSUSE Tumbleweed< 0.74.0-1.1
  • v2ray-core&distro=openSUSE Tumbleweed< 5.53.0-1.1
Debian1 product
  • golang-github-go-chi-chiAll versions (No fix recorded) | < 5.3.0-1
Github.com/go-chi/chi/v21 product
  • middleware≤ 2.1.1
Github.com/go-chi/chi/v31 product
  • middleware≤ 3.3.5
Github.com/go-chi/chi/v41 product
  • middleware≤ 4.1.3
Github.com/go-chi/chi/v51 product
  • middleware< 5.3.0
Go-chi1 product
  • chi≥ 0.9.0, < 5.3.0
Ubuntu1 product
  • golang-github-go-chi-chiAll versions (No fix recorded)

9 vendors · 11 products

References

10 links