Vulnerability · Published Oct 14, 2026 · Assigned by EEF
CVE-2026-94200TLS 1.3 client ticket store crashed by NewSessionTicket with empty early_data extension in ssl
High 8.2
In plain English
A high-severity security flaw in OTP from Erlang. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Improper Validation of Consistency within Input vulnerability in Erlang OTP ssl (tls_handshake_1_3, ssl_handshake and tls_client_ticket_store modules) allows a malicious TLS 1.3 server to cause a denial of service of the ssl application on the client node. The TLS 1.3 client decodes the extensions of a NewSessionTicket message as if they came from EncryptedExtensions. It therefore accepts a 0-length early_data extension, a form that is only valid in ClientHello and EncryptedExtensions. With {session_tickets, auto}, the client stores the ticket in the node-global tls_client_ticket_store. On the next automatic resumption, tls_handshake_1_3:get_max_early_data/1 crashes the store with a case_clause. Repeated crashes can exceed the restart intensity of the ssl supervisors, which use the rest_for_one strategy, and take down ssl for all connections on the node. This issue affects OTP from OTP 23.3 before OTP 27.3.4.19, OTP 28.5.0.8, and OTP 29.1.2, corresponding to ssl from 10.3 before 11.2.12.14, 11.6.0.7, and 11.7.8.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | erlang | no fix listed | DEBIAN-CVE-2026-94200 |
| Debian:13 | erlang | no fix listed | DEBIAN-CVE-2026-94200 |
| Debian:14 | erlang | 1:29.1.2+dfsg-1 | DEBIAN-CVE-2026-94200 |
| Ubuntu:22.04:LTS | erlang | no fix listed | UBUNTU-CVE-2026-94200 |
| Ubuntu:24.04:LTS | erlang | no fix listed | UBUNTU-CVE-2026-94200 |
| Ubuntu:26.04:LTS | erlang | no fix listed | UBUNTU-CVE-2026-94200 |
| Ubuntu:26.10 | erlang | no fix listed | UBUNTU-CVE-2026-94200 |
Affected products (as reported)
Weakness: CWE-1288 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
References
- GitHub Advisory related, vendor-advisory
- EEF CNA record for CVE-2026-94200 related
- OSV record EEF-CVE-2026-94200 related
- Erlang/OTP version ordering x_version-scheme
- Introducing commit 0abe6f6 in erlang/otp related
- Fix commit 66febc1 in erlang/otp patch
- Fix commit 00a333b in erlang/otp patch
- Fix commit cd03348 in erlang/otp patch