Bug 2487597 (CVE-2026-48860)

Summary: CVE-2026-48860 erlang: Erlang/OTP: Authentication bypass allows arbitrary code execution via improper IP address validation
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: eglynn, jjoyce, jpretori, jschluet, lhh, mburns, mgarciac
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in Erlang/OTP. The `inet_tls_dist:check_ip/1` function, responsible for enforcing a LAN allowlist for Erlang distribution over TLS, incorrectly uses `inet:sockname/1` instead of `inet:peername/1` to obtain the peer's IP address. This allows an unauthenticated attacker, possessing a CA-signed TLS certificate, to bypass the LAN restriction. Consequently, the attacker can gain full Erlang distribution access to the node, enabling remote procedure calls and arbitrary code loading.
 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: 2490271, 2490272    
Bug Blocks:    

Description OSIDB Bzimport 2026-06-10 16:01:37 UTC 
Reliance on IP Address for Authentication vulnerability in Erlang/OTP ssl (inet_tls_dist module) allows unauthenticated bypass of the distribution-over-TLS LAN allowlist.

The inet_tls_dist:check_ip/1 function, which enforces a LAN allowlist for Erlang distribution over TLS, calls inet:sockname/1 instead of inet:peername/1 to obtain the peer's IP address. Because inet:sockname/1 returns the local socket address, both the local IP and the supposed peer IP resolve to the same value, causing the subnet mask comparison to always succeed regardless of the actual remote address. Any holder of a CA-signed TLS certificate can therefore bypass the LAN restriction and gain full Erlang distribution access to the node, including rpc:call/4 and code:load_binary/3.

This vulnerability is associated with program file lib/ssl/src/inet_tls_dist.erl.

This issue affects OTP from OTP 26.0 before 29.0.2, 28.5.0.2 and 27.3.4.13 corresponding to ssl from 11.0 before 11.7.2, 11.6.0.2 and 11.2.12.9.