6.9

CVE-2026-72816: go-chi chi before 5.3.0 IP Spoofing via RealIP Middleware

Deferred
AliasesUBUNTU-CVE-2026-72816DEBIAN-CVE-2026-72816GHSA-rjr7-jggh-pgcp
Published 14-08-2026Last modified 08-10-2026

Vulnerability summary

CVE-2026-72816 is a medium (CVSS 6.9) Authentication Bypass by Spoofing vulnerability in go-chi chi. EPSS estimates a 0.30% chance of exploitation in the next 30 days, higher than 22.8% 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
0.30%
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 8 · Related 6
OPENSUSE-SU-2026:21645-1OPENSUSE-SU-2026:21653-1OPENSUSE-SU-2026:21670-1OPENSUSE-SU-2026:21793-1OPENSUSE-SU-2026:21918-1RHSA-2026:49718

Timeline

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

Description

go-chi/chi through 5.2.1 contains an IP spoofing vulnerability in the RealIP middleware (middleware/realip.go). The realIP() function reads client-controlled headers (True-Client-IP, X-Real-IP, and X-Forwarded-For) and overwrites r.RemoteAddr without verifying that the request originated from a trusted proxy. Attackers can supply arbitrary IP addresses in these headers to bypass IP-based access controls, evade rate limiting and geo-IP restrictions, and pollute audit logs. Fixed in 5.3.0.

CVSS metrics

8 scores · 5 sources · 2 versions

EPSS trend

Probability

0.30%

Chance of exploitation in the next 30 days

Percentile

23%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.30% 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≤ 1.5.5
  • v5< 5.3.0
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
Ubuntu1 product
  • golang-github-go-chi-chiAll versions (No fix recorded)

8 vendors · 9 products

References

9 links