Medium [CVE-2026-72817] IP spoofing via X-Forwarded-For header manipulation
This medium-severity Red Hat Linux advisory covers CVE-2026-72817 affecting Cryostat 4, External Secrets Operator for Red Hat OpenShift, Gatekeeper 3.
Android app · Google Play
Monitor future Red Hat Linux CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 32 official vendor sources and 160+ reviewed platform categories.
Summary
A flaw was found in the `go-chi/chi` component. The RealIP middleware, responsible for resolving the request source IP, does not properly validate trusted proxies when processing the `X-Forwarded-For` header.
A remote attacker can exploit this by prepending a forged IP address to the `X-Forwarded-For` header, leading to IP spoofing. This could allow the attacker to bypass access controls or falsify request logs.
A flaw in the go-chi/chi RealIP middleware allows remote attackers to spoof source IP addresses (`Request. RemoteAddr`).
The middleware parses the first IP address in the `X-Forwarded-For` header without verifying if the immediate HTTP proxy peer is trusted. An unauthenticated attacker can prepend an arbitrary IP address to the `X-Forwarded-For` header, causing applications relying on `RealIP` for request context to misidentify the client source.
This enables bypassing application-level IP-based access control lists (ACLs) or spoofing identity in audit logs. Red Hat severity: Moderate — CVSS 6.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N).
Weakness: CWE-501.
Affected products named by the advisory: Cryostat 4; External Secrets Operator for Red Hat OpenShift; Gatekeeper 3; Logging Subsystem for Red Hat OpenShift; and 19 more.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · high-confidence parse· fetched 1 hour ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · high-confidence parse· fetched 1 hour ago·verify at source
Mitigation checklist
- Disable the default `RealIP` middleware and replace it with a proxy-aware middleware (such as `httputil.ReverseProxy` or custom header parsing) that strictly validates upstream reverse proxies against an explicit list of trusted CIDR ranges before accepting `X-Forwarded-For` headers.
Official advisory · high-confidence parse· fetched 1 hour ago·verify at source
Discussion(0)
No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.
Sign in to join the discussion.