# CVE-2026-58227: TLS/DTLS denial of service via unbounded recursion on cross-signed peer certificate chain

> Remote attackers can crash Erlang/OTP nodes by sending crafted cross-signed certificate chains that trigger unbounded recursion during TLS/DTLS handshakes.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 Jul 2026
- **Updated:** 28 Jul 2026
- **Also known as:** AZL-94205, DEBIAN-CVE-2026-58227, EEF-CVE-2026-58227, GHSA-r5jr-mq46-vmhw, UBUNTU-CVE-2026-58227

## What is CVE-2026-58227?

CVE-2026-58227 is a high-severity denial of service vulnerability in Erlang OTP, published on 27 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Erlang/OTP ssl application does not detect cycles when reconstructing an incomplete peer certificate chain during a TLS or DTLS handshake. In ssl_certificate:handle_incomplete_chain/5, the received chain is passed to ssl_certificate:build_certificate_chain/5, which walks issuer relationships via ssl_certificate:do_certificate_chain/7 with no cycle detection and no depth limit. When the peer supplies two mutually cross-signed certificates in unordered form (A issues B, B issues A), the issuer lookup alternates between the two certificates and the pair of functions recurses indefinitely, growing the call stack and chain accumulator without bound.

An unauthenticated remote attacker can send a crafted certificate chain in a TLS or DTLS Certificate handshake message to exhaust available memory and crash the BEAM node. Only a TCP connection and a partial handshake are required; no authentication or completed handshake is needed, and both TLS/DTLS servers and clients are affected when processing peer certificate messages.

This issue affects OTP from OTP 23.2 before OTP 29.0.4, OTP 28.5.0.4 and OTP 27.3.4.15, corresponding to ssl from 10.2 before 11.7.4, 11.6.0.4 and 11.2.12.11.

Weakness: CWE-674 (Uncontrolled Recursion)

## Which versions are affected by CVE-2026-58227?

It affects 2 products.


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

## How do I fix CVE-2026-58227?

Upgrade to a fixed version.

## Is CVE-2026-58227 being exploited?

There is no known exploitation of CVE-2026-58227 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-2026-59251](https://insights.sbomify.com/CVE-2026-59251/): Denial of service via exponential certificate policy tree growth in path validation (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-58227 and fix it if it is affected.

What it is: CVE-2026-58227 is a high-severity denial of service vulnerability in Erlang OTP, published on 27 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-58227 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-2026-58227/ (Markdown: https://insights.sbomify.com/CVE-2026-58227/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-58227
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-58227
- OSV: https://osv.dev/vulnerability/CVE-2026-58227

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-58227/
Summaries are generated and may contain mistakes; the official description above is the record.