Read the docs
TI-2025-21547 Aliases CVE-2025-30211

KEX init error results with excessive memory usage

Priority LOW 39CWE-789Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-789.

Summary

Erlang/OTP is a set of libraries for the Erlang programming language. Prior to versions OTP-27.3.1, 26.2.5.10, and 25.3.2.19, a maliciously formed KEX init message can result with high memory usage. Implementation does not verify RFC specified limits on algorithm names (64 characters) provided in KEX init message. Big KEX init packet may lead to inefficient processing of the error data. As a result, large amount of memory will be allocated for processing malicious data. Versions OTP-27.3.1, OTP-26.2.5.10, and OTP-25.3.2.19 fix the issue. Some workarounds are available. One may set option `parallel_login` to `false` and/or reduce the `max_sessions` option.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00472 41st percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Erlangotp< OTP-27.3.1; < OTP-26.2.5.10; < OTP-25.3.2.19—No fix listedCNA
  • otp VendorErlang Affected < OTP-27.3.1; < OTP-26.2.5.10; < OTP-25.3.2.19 Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

Not affected: 3 products
  • Red Hat OpenStack Platform 16.2
  • Red Hat OpenStack Platform 17.1
  • Red Hat OpenStack Platform 18.0

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-30211

References

Other 1

  • TI-2025-23504 Erlang/OTP SSH Vulnerable to Pre-Authentication RCE KEVCVSS 3.1CRITICAL 10.0
  • TI-2026-48954 httpd parks a request worker indefinitely on a malformed chunk size sent after the headers CVSS 4.0HIGH 8.7
  • TI-2023-26623 The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6… CVSS 3.1MEDIUM 5.9
  • TI-2026-71037 Path traversal in rebar3 via unvalidated dependency app names CVSS 4.0HIGH 7.5
  • TI-2024-36042 ssl fails to validate incorrect extened key usage CVSS 3.1MEDIUM 5.5
  • TI-2020-10791 Rebar3 versions 3.0.0-beta.3 to 3.13.2 are vulnerable to OS command injection via URL… CVSS 3.1CRITICAL 9.8
See all 80 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences