Cyber Resilience

CVE-2026-55952

Erlang\/Otp 22.2 – 27.3.4.14

Published
02 July 2026
Modified
24 July 2026
Patch / advisory
View advisory
CVSS Score v4 8.2
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0048 39th percentile
Risk Priority 44 floored blend · peak EPSS

Summary

CVE-2026-55952 is a high-severity Improper Validation of Specified Quantity in Input (CWE-1284) vulnerability in Erlang Erlang\/Otp. Its CVSS base score is 8.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 39th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)
CWE-1284

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-48860Same product: Erlang Erlang\/Otp
CVE-2026-58227Same product: Erlang Erlang\/Otp
CVE-2026-54887Same product: Erlang Erlang\/Otp
CVE-2026-54891Same product: Erlang Erlang\/Otp
CVE-2026-55950Same product: Erlang Erlang\/Otp
CVE-2026-55953Same product: Erlang Erlang\/Otp
CVE-2026-54890Same product: Erlang Erlang\/Otp
CVE-2026-49760Same product: Erlang Erlang\/Otp
CVE-2026-49759Same product: Erlang Erlang\/Otp
CVE-2026-42791Same product: Erlang Erlang\/Otp

Affected Assets

erlang
erlang\/otp
22.2 — 27.3.4.14 · 28.0 — 28.5.0.3 · 29.0 — 29.0.3
erlang
erlang\/ssl
9.5 — 11.2.12.10 · 11.3 — 11.6.0.3 · 11.7 — 11.7.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V6.7.2
  • V1.4.2
  • V2.1.1
  • V2.2.1

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match

SI-10 requires validity checks on information inputs, directly stopping acceptance of malformed quantities before they can be used.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require proper quantity/length validation in input handling.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development can detect missing quantity validation but does not itself implement the control.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates input validation for quantity fields, directly preventing CWE-1284.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly call for validation of size/length inputs, mitigating CWE-1284.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles encourage robust input handling but do not specifically address quantity validation.

A.8.28 Secure coding partial match
prevents

Secure coding standards require explicit checks on numeric quantity inputs, fully addressing CWE-1284.

References