Bug 2518009

Summary:	CVE-2026-72816 opkssh: go-chi/chi: IP Spoofing via RealIP Middleware allows bypassing access controls [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Joel Chamberlain <jochambe>
Component:	opkssh	Assignee:	Till Hofmann <thofmann>
Status:	ON_QA ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	rawhide	CC:	go-sig, thofmann
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["5fca9e5b-6b38-4e4b-9b95-a3e49b4c5b98"]}
Fixed In Version:		Doc Type:	---
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2515985

Description Joel Chamberlain 2026-08-18 16:12:11 UTC

Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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.

Comment 1 Fedora Update System 2026-08-19 08:38:18 UTC

FEDORA-2026-f5a5073561 (opkssh-0.16.0-2.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-f5a5073561

Comment 2 Fedora Update System 2026-08-19 08:39:09 UTC

FEDORA-2026-8d9ba295e0 (opkssh-0.16.0-2.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-8d9ba295e0

Comment 3 Fedora Update System 2026-08-20 16:39:24 UTC

FEDORA-2026-f5a5073561 has been pushed to the Fedora 44 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-f5a5073561`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-f5a5073561

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 4 Fedora Update System 2026-08-20 16:40:00 UTC

FEDORA-2026-8d9ba295e0 has been pushed to the Fedora 43 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-8d9ba295e0`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-8d9ba295e0

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.