# CVE-2026-94200: Erlang OTP ssl denial of service in TLS 1.3 NewSessionTicket

Source: https://junglewise.ai/threats/cve-2026-94200-improper-validation-of-consistency-within-input-vulnerability-in  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-14. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-94200 · Severity: info · Published 2026-10-14

Erlang OTP's TLS 1.3 implementation incorrectly validates NewSessionTicket messages, allowing a malicious server to crash the session ticket store. By sending a specially crafted ticket, an attacker can cause the entire TLS stack on the affected node to fail, disrupting all encrypted connections until the application restarts.

Technologies: [Erlang OTP](https://junglewise.ai/threats/technologies/otp). Vendors: [Erlang](https://junglewise.ai/threats/vendors/erlang).

## Quick answers

**Is CVE-2026-94200 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-94200 being exploited in the wild.

**How severe is CVE-2026-94200?** Informational severity, published 14 October 2026.

**Which products and versions are affected?** Erlang OTP 23.3 before 27.3.4.19, 28.x before 28.5.0.8, 29.x before 29.1.2.

**Is there a fix for CVE-2026-94200?** Yes: fixed in OTP 27.3.4.19, OTP 28.5.0.8, OTP 29.1.2 (corresponding to ssl 11.2.12.14, 11.6.0.7, 11.7.8). Until then: Set {session_tickets, manual} or use the default {session_tickets, disabled} to disable automatic session ticket resumption on TLS 1.3 clients; only clients with automatic resumption enabled are vulnerable. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-94200 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-94200?** Check whether you run Erlang OTP at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in OTP 27.3.4.19, OTP 28.5.0.8, OTP 29.1.2 (corresponding to ssl 11.2.12.14, 11.6.0.7, 11.7.8)

Set {session_tickets, manual} or use the default {session_tickets, disabled} to disable automatic session ticket resumption on TLS 1.3 clients; only clients with automatic resumption enabled are vulnerable.

## Technical details

A TLS 1.3 client using session ticket auto-resumption mishandles NewSessionTicket extensions: it decodes them with the wrong message type (encrypted_extensions instead of new_session_ticket), accepting a malformed early_data extension. When resuming a session with this corrupt ticket, the get_max_early_data function crashes with a case_clause error. Repeated crashes trigger the supervisor's restart limit, taking down the entire SSL application; exploitation requires a controlled or impersonated server.

## Affected products

- Erlang OTP 23.3 before 27.3.4.19, 28.x before 28.5.0.8, 29.x before 29.1.2

## Timeline

- 2026-10-14: disclosed

## References

- [https://github.com/](https://github.com/)
- [https://cna.erlef.org/cves/CVE-2026-94200.html](https://cna.erlef.org/cves/CVE-2026-94200.html)

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