CVE-2026-72817
go-chi chi 0.9.0 before 5.3.0 IP Spoofing via X-Forwarded-For
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.
INFO
Published Date :
Aug. 14, 2026, 12:16 p.m.
Last Modified :
Oct. 8, 2026, 4:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 4.0 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update go-chi/chi to version 5.3.0 or later.
- Configure trusted proxies for RealIP middleware.
- Validate X-Forwarded-For header before trusting IPs.
- Ensure request source IP is accurately determined.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-72817.
| URL | Resource |
|---|---|
| https://github.com/go-chi/chi/security/advisories/GHSA-9g5q-2w5x-hmxf | |
| https://www.vulncheck.com/advisories/go-chi-chi-before-ip-spoofing-via-x-forwarded-for |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-72817 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-72817
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-72817 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-72817 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.
-
CVE Modified by [email protected]
Oct. 08, 2026
Action Type Old Value New Value Added Affected Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/72xxx/CVE-2026-72817.json">CVE-2026-72817</a> Added Reference https://github.com/go-chi/chi/security/advisories/GHSA-9g5q-2w5x-hmxf Added Reference https://www.vulncheck.com/advisories/go-chi-chi-before-ip-spoofing-via-x-forwarded-for Removed Reference https://github.com/go-chi/chi/security/advisories/GHSA-9g5q-2w5x-hmxf Removed Reference https://www.vulncheck.com/advisories/go-chi-chi-before-ip-spoofing-via-x-forwarded-for -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-72817', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-17T15:44:55.846871Z'} -
New CVE Received by [email protected]
Aug. 14, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'go-chi', 'product': 'chi', 'versions': [{'status': 'affected', 'version': '0.9.0', 'lessThan': '5.3.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.3.0', 'versionType': 'semver'}], 'packageURL': 'pkg:golang/github.com/go-chi/chi/middleware', 'defaultStatus': 'unaffected'}] Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/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 CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N Added CWE CWE-345 Added Reference https://github.com/go-chi/chi/security/advisories/GHSA-9g5q-2w5x-hmxf Added Reference https://www.vulncheck.com/advisories/go-chi-chi-before-ip-spoofing-via-x-forwarded-for