CVE-2025-30211Network attack vector

Unauthenticated memory exhaustion via oversized KEXINIT names

Published Mar 28, 2025 · Updated Nov 3, 2025

Denial of service in Erlang/OTP SSH allows remote attackers to exhaust memory through a malicious KEXINIT message. The SSH KEXINIT handler fails to enforce the RFC's 64-character limit on algorithm names and inefficiently constructs error data for an oversized packet. An unauthenticated client that can reach an enabled Erlang SSH daemon can consume large amounts of host memory; no data disclosure or modification is reported.

CVSS severity7.5
High
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Erlang/OTP SSH allows remote attackers to exhaust memory through a malicious KEXINIT message. The SSH KEXINIT handler fails to enforce the RFC's 64-character limit on algorithm names and inefficiently constructs error data for an oversized packet. An unauthenticated client that can reach an enabled Erlang SSH daemon can consume large amounts of host memory; no data disclosure or modification is reported.

The record

CVE
CVE-2025-30211
Published
Mar 28, 2025
Updated
Nov 3, 2025
Vendor
Erlang
Product
Erlang/OTP
Classifications
CWE-789, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 28, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=< OTP-25.3.2.19
  2. Affected versionversion=< OTP-26.2.5.10
  3. Affected versionversion=< OTP-27.3.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Erlang · Erlang/OTPversion=< OTP-25.3.2.19; version=< OTP-26.2.5.10; version=< OTP-27.3.1

Published CVSS scores

7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-789Memory Allocation with Excessive Size Value
T1499.003Application Exhaustion Flood

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

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Your stack

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