CVE-2026-48860: Distribution-over-TLS LAN allowlist silently bypassed due to sockname/peername confusion in inet_tls_dist
Distribution-over-TLS LAN allowlist silently bypassed due to sockname/peername confusion in inettlsdist
Other sources
Reliance on IP Address for Authentication vulnerability in Erlang/OTP ssl (inettlsdist module) allows unauthenticated bypass of the distribution-over-TLS LAN allowlist.
The inettlsdist:checkip/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:loadbinary/3.
This vulnerability is associated with program file lib/ssl/src/inettlsdist.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.
— NVD
Reliance on IP Address for Authentication vulnerability in Erlang/OTP ssl (inettlsdist module) allows unauthenticated bypass of the distribution-over-TLS LAN allowlist.
The inettlsdist:checkip/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:loadbinary/3.
This vulnerability is associated with program file lib/ssl/src/inettlsdist.erl.
This issue affects OTP from OTP 26.0 before OTP 29.0.2, OTP 28.5.0.2 and OTP 27.3.4.13, corresponding to ssl from 11.0 before 11.7.2, 11.6.0.2 and 11.2.12.9.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 26.2.5.21-2 - Upgrade
Upgrade
Erlang/OTP ssl (inet_tls_dist)to a version that resolves this vulnerability.Fixed in 29.0.2 - Upgrade
Upgrade
Erlang/OTP ssl (inet_tls_dist)to a version that resolves this vulnerability.Fixed in 28.5.0.2 - Upgrade
Upgrade
Erlang/OTP ssl (inet_tls_dist)to a version that resolves this vulnerability.Fixed in 27.3.4.13 - Upgrade
Upgrade
Erlang/OTP ssl (inet_tls_dist)to a version that resolves this vulnerability.Fixed in 11.7.2 - Upgrade
Upgrade
Erlang/OTP ssl (inet_tls_dist)to a version that resolves this vulnerability.Fixed in 11.6.0.2 - Upgrade
Upgrade
Erlang/OTP ssl (inet_tls_dist)to a version that resolves this vulnerability.Fixed in 11.2.12.9
Event History
Frequently Asked Questions
What is the severity of CVE-2026-48860?
CVE-2026-48860 has a high severity rating of 7.5 based on the CVSS scoring.
How do I fix CVE-2026-48860?
To fix CVE-2026-48860, ensure that you apply the latest updates from Erlang/OTP that address this vulnerability.
What type of vulnerability is CVE-2026-48860?
CVE-2026-48860 is a reliance on IP address for authentication vulnerability affecting the erl_tls_dist module.
What are the potential impacts of CVE-2026-48860?
The vulnerability allows for an unauthenticated bypass of the distribution-over-TLS LAN allowlist, which could lead to unauthorized access.
Which software is affected by CVE-2026-48860?
CVE-2026-48860 affects Erlang OTP and Erlang SSL modules.