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

> Attackers with valid TLS certificates can bypass LAN allowlists in Erlang distribution to execute arbitrary code and escalate privileges.

- **Severity:** High 7.5 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Jun 2026
- **Updated:** 24 Sep 2026
- **Also known as:** AZL-90123, DEBIAN-CVE-2026-48860, EEF-CVE-2026-48860, GHSA-gp7x-mfv6-52cv, UBUNTU-CVE-2026-48860

## What is CVE-2026-48860?

CVE-2026-48860 is a high-severity authentication bypass vulnerability in Erlang OTP, published on 10 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official 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.

Weakness: CWE-863 (Incorrect Authorization), CWE-1025 (Comparison Using Wrong Factors)

## Which versions are affected by CVE-2026-48860?

It affects 2 products.


Products: Erlang Erlang\/Otp, Erlang Erlang\/Ssl.

## How do I fix CVE-2026-48860?

Upgrade to a fixed version.

## Is CVE-2026-48860 being exploited?

There is no known exploitation of CVE-2026-48860 in the wild and no public exploit code.

## Other vulnerabilities in Erlang OTP

- [CVE-2022-37026](https://insights.sbomify.com/CVE-2022-37026/): Auth bypass in n/a (critical 9.8)
- [CVE-2016-10253](https://insights.sbomify.com/CVE-2016-10253/): Memory corruption in n/a (critical 9.8)
- [CVE-2026-55953](https://insights.sbomify.com/CVE-2026-55953/): TLS 1.2 and DTLS client accepts unoffered anonymous cipher suite, bypassing server authentication (critical 9.1)
- [CVE-2026-49759](https://insights.sbomify.com/CVE-2026-49759/): Stack buffer overflow in SCTP error cause parsing in inet_drv allows remote VM crash (high 8.8)
- [CVE-2026-58227](https://insights.sbomify.com/CVE-2026-58227/): TLS/DTLS denial of service via unbounded recursion on cross-signed peer certificate chain (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-48860 and fix it if it is affected.

What it is: CVE-2026-48860 is a high-severity authentication bypass vulnerability in Erlang OTP, published on 10 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-48860 in the wild and no public exploit code.

Affected product: Erlang OTP. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-48860/ (Markdown: https://insights.sbomify.com/CVE-2026-48860/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-48860
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-48860
- OSV: https://osv.dev/vulnerability/CVE-2026-48860

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-48860/
Summaries are generated and may contain mistakes; the official description above is the record.