CVE-2026-21619Network attack vector

VM crash via unrestricted Erlang term deserialization

Published Feb 27, 2026 · Updated Feb 27, 2026

Unsafe deserialization in Hex API clients for Hex, hex_core, and Rebar3 allows remote attackers to crash the Erlang VM via API responses. The request/4 routines pass Erlang-term response bodies to binary_to_term/1 without the safe option, allowing untrusted terms to create atoms until the atom table is exhausted. Exploitation requires control of the configured API response and a user-initiated client request; exhaustion crashes the VM, and released versions are not known to permit code execution.

CVSS severity2.0
Low
EPSS probability0.58%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Unsafe deserialization in Hex API clients for Hex, hex_core, and Rebar3 allows remote attackers to crash the Erlang VM via API responses. The request/4 routines pass Erlang-term response bodies to binary_to_term/1 without the safe option, allowing untrusted terms to create atoms until the atom table is exhausted. Exploitation requires control of the configured API response and a user-initiated client request; exhaustion crashes the VM, and released versions are not known to permit code execution.

The record

CVE
CVE-2026-21619
Published
Feb 27, 2026
Updated
Feb 27, 2026
Vendor
Six Colors AB
Product
Hex
Classifications
CWE-502, CWE-400, CAPEC-586, CAPEC-130, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.3.0 <2.3.2
  2. Affected versionversion=314546ac432229518714cc8e3336e916b9da6305 <636739f3322514e9303ca335fb630696fcbb3c95
  3. Affected versionversion=pkg:otp/[email protected] <pkg:otp/[email protected]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Six Colors AB · Hexversion=2.3.0 <2.3.2; version=314546ac432229518714cc8e3336e916b9da6305 <636739f3322514e9303ca335fb630696fcbb3c95; version=pkg:otp/[email protected] <pkg:otp/[email protected]
Erlang · Rebar3version=209c02ec57c2cc3207ee0174c3af3675b8dc8f79 <1d4478f527e373de0b225951e53115450e0d9b9d; version=3.9.1 <3.27.0; version=pkg:otp/[email protected] <pkg:otp/[email protected]
Six Colors AB · hex_coreversion=0.1.0 <0.12.1; version=eb327f8edfe45507351e38cc0805aa12fa647f0b <cdf726095bca85ad2549d146df1e831ae93c2b13; version=pkg:hex/[email protected] <pkg:hex/[email protected]

Published CVSS scores

2.0Erlang Ecosystem FoundationCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
CWE-400Uncontrolled Resource Consumption
CAPEC-586Object Injection
CAPEC-130Excessive Allocation
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo