Denial of service via unchecked SFTP reassembly
Published Feb 20, 2025 · Updated Nov 3, 2025
Denial of service in Erlang/OTP SSH allows remote authenticated users to exhaust server memory through oversized SFTP packets. The ssh_sftpd handle_data function concatenates fragments from multiple valid-size SSH messages into a pending SFTP binary without enforcing the SSH maximum packet size. Successful SSH authentication and an enabled SFTP subsystem are required; sustained allocation can interrupt the Erlang SSH service or its host.
Summary
What happened
Denial of service in Erlang/OTP SSH allows remote authenticated users to exhaust server memory through oversized SFTP packets. The ssh_sftpd handle_data function concatenates fragments from multiple valid-size SSH messages into a pending SFTP binary without enforcing the SSH maximum packet size. Successful SSH authentication and an enabled SFTP subsystem are required; sustained allocation can interrupt the Erlang SSH service or its host.
The record
- CVE
- CVE-2025-26618
- Published
- Feb 20, 2025
- Updated
- Nov 3, 2025
- Vendor
- Erlang
- Product
- Erlang/OTP
- Classifications
- CWE-789, T1499.003
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 20, 2025CVE publishedPublication date reported by the CVE source.
- Nov 3, 2025Record 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.
- Affected versionversion=< OTP-25.3.2.18
- Affected versionversion=>= OTP-26.0.0.0, < OTP-26.2.5.9
- Affected versionversion=>= OTP-27.0.0, < OTP-27.2.4
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
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