SSH SFTP packet size not verified properly in Erlang OTP
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-789.
Summary
Erlang is a programming language and runtime system for building massively scalable soft real-time systems with requirements on high availability. OTP is a set of Erlang libraries, which consists of the Erlang runtime system, a number of ready-to-use components mainly written in Erlang. Packet size is not verified properly for SFTP packets. As a result when multiple SSH packets (conforming to max SSH packet size) are received by ssh, they might be combined into an SFTP packet which will exceed the max allowed packet size and potentially cause large amount of memory to be allocated. Note that situation described above can only happen for successfully authenticated users after completing the SSH handshake. This issue has been patched in OTP versions 27.2.4, 26.2.5.9, and 25.3.2.18. There are no known workarounds for this vulnerability.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. 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
- 2026-10-02 Threatist record created from CVE-2025-26618
References
More Erlang vulnerabilities
- 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
Sources
- CVE-2025-26618 · CVE Program
- CVE-2025-26618 · NVD
- FIRST EPSS
- CVE-2025-26618 · Red Hat security data · CC BY 4.0
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