CVE-2026-55952— TLS 1.3 server denial of service via malformed ClientHello pre-shared key extension
Quick assessment
Affected
Erlang OTP
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
erlang erlang/otp是erlang社区开源的一套并发编程语言及运行时系统。 Erlang/OTP存在输入验证错误漏洞，该漏洞源于ssl application未验证TLS 1.3 ClientHello预共享密钥扩展中PSK身份列表和绑定列表的长度是否相等，可能导致未经身份验证的远程攻击者发送特制ClientHello，造成会话票据处理进程崩溃，使TLS 1.3不可用。
Possible ATT&CK Techniques 2 AI
T1190 · Exploit Public-Facing Application T1499 · Endpoint Denial of Service
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I. Basic Information for CVE-2026-55952
Vulnerability Information
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Vulnerability Title
TLS 1.3 server denial of service via malformed ClientHello pre-shared key extension
Source: CVE Program / CVE List V5
Vulnerability Description
The Erlang/OTP ssl application does not validate that the PSK identity list and binder list carried in a TLS 1.3 ClientHello pre-shared key extension have equal length before passing them to the session ticket handler. In tls_handshake_1_3:handle_pre_shared_key/3, an OfferedPreSharedKeys record with a mismatched number of identities and binders is forwarded directly to tls_server_session_ticket:use/4, which crashes the session ticket handler process.
An unauthenticated remote attacker can send a single crafted ClientHello to a TLS 1.3 server with session tickets enabled (stateful or stateless mode) and permanently disrupt session ticket handling on that listener. New TLS 1.3 handshakes complete but subsequently crash when the server attempts to issue a session ticket, effectively making TLS 1.3 unusable on the affected listener until the ssl application is restarted. TLS 1.2 connections are not affected.
This issue affects OTP from OTP 22.2 before OTP 29.0.3, OTP 28.5.0.3 and OTP 27.3.4.14, corresponding to ssl from 9.5 before 11.7.3, 11.6.0.3 and 11.2.12.10.
Source: CVE Program / CVE List V5
CVSS Information
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
Source: CVE Program / CVE List V5
Vulnerability Type
CWE-1284
Source: CVE Program / CVE List V5
Vulnerability Title
Erlang/OTP 输入验证错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
erlang erlang/otp是erlang社区开源的一套并发编程语言及运行时系统。 Erlang/OTP存在输入验证错误漏洞，该漏洞源于ssl application未验证TLS 1.3 ClientHello预共享密钥扩展中PSK身份列表和绑定列表的长度是否相等，可能导致未经身份验证的远程攻击者发送特制ClientHello，造成会话票据处理进程崩溃，使TLS 1.3不可用。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
II. Public POCs for CVE-2026-55952
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Patches & Fixes for CVE-2026-55952 (3)
Vendor Advisories for CVE-2026-55952 (3)
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🔗 EEF-CVE-2026-55952 - OSV related
Same Patch Batch · Erlang · 2026-07-02 · 6 CVEs total
| CVE-2026-55950 | 8.7 HIGH | DTLS listener crash via race condition in dtls_packet_demux causes denial of service for a |
| CVE-2026-54887 | 6.3 MEDIUM | DTLS server cookie bypass during startup window due to empty initial cookie secret |
| CVE-2026-54891 | 6.3 MEDIUM | Plaintext APPLICATION_DATA injected during TLS handshake delivered to client application p |
| CVE-2026-54886 | 5.3 MEDIUM | SSH SFTP server denial of service via extended channel data infinite loop |
| CVE-2026-53422 | 2.3 LOW | SFTP REALPATH path-existence oracle allowing filesystem enumeration outside configured roo |
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