Cyber Resilience

CVE-2026-32147

Path Traversal in Erlang\/Otp 17.0 – 26.2.5.20

Published
21 April 2026
Modified
24 July 2026
Patch / advisory
CVSS Score v4 5.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0035 28th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-32147 is a medium-severity Path Traversal (CWE-22) vulnerability in Erlang Erlang\/Otp. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 28th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-6 (Least Privilege) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Erlang OTP ssh (ssh_sftpd module) allows an authenticated SFTP user to modify file attributes outside the configured chroot directory. The SFTP daemon (ssh_sftpd) stores the raw, user-supplied…

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path in file handles instead of the chroot-resolved path. When SSH_FXP_FSETSTAT is issued on such a handle, file attributes (permissions, ownership, timestamps) are modified on the real filesystem path, bypassing the root directory boundary entirely. Any authenticated SFTP user on a server configured with the root option can modify file attributes of files outside the intended chroot boundary. The prerequisite is that a target file must exist on the real filesystem at the same relative path. Note that this vulnerability only allows modification of file attributes; file contents cannot be read or altered through this attack vector. If the SSH daemon runs as root, this enables direct privilege escalation: an attacker can set the setuid bit on any binary, change ownership of sensitive files, or make system configuration world-writable. This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl and program routines ssh_sftpd:do_open/4 and ssh_sftpd:handle_op/4. This issue affects OTP from OTP 17.0 before OTP 28.4.3, OTP 27.3.4.11 and OTP 26.2.5.20, corresponding to ssh from 3.0.1 before 5.5.3, 5.2.11.7 and 5.1.4.15.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1222.002 Linux and Mac Permissions Defense Impairment
Adversaries may modify file or directory permissions/attributes to evade access control lists (ACLs) and access protected files.
Why these techniques?

Path traversal in ssh_sftpd enables authenticated modification of file permissions/ownership outside chroot; when daemon runs as root this directly yields privilege escalation via setuid/ownership changes (T1068) and is an instance of permissions modification (T1222.002).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-23942Same product: Erlang Erlang\/Otp
CVE-2025-54307Shared CWE-22
CVE-2026-28827Shared CWE-22
CVE-2025-6020Shared CWE-22
CVE-2025-55282Shared CWE-22
CVE-2024-48885Shared CWE-22
CVE-2026-20982Shared CWE-22
CVE-2026-45171Shared CWE-22
CVE-2026-20688Shared CWE-22
CVE-2026-28915Shared CWE-22

Affected Assets

erlang
erlang\/otp
17.0 — 26.2.5.20 · 27.0 — 27.3.4.11 · 28.0 — 28.4.3
erlang
erlang\/ssh
3.0.1 — 5.1.4.15 · 5.2 — 5.2.11.7 · 5.5 — 5.5.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • AC-6 Least Privilege
  • SI-10 Information Input Validation
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V5.3.2

Mitigating Controls (NIST 800-53 r5) AI

prevent

Enforces the configured chroot directory boundary so that SFTP file-handle operations (FSETSTAT) cannot affect paths outside the restricted directory.

prevent

Ensures the sshd process and SFTP sessions run with only the privileges required for the chroot, eliminating root-level attribute changes that enable privilege escalation.

prevent

Validates and canonicalizes user-supplied pathnames in do_open/handle_op before storing file handles, preventing raw-path bypass of the chroot.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-02 partial match
prevents

Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.

PR.AA-05 none match
prevents

PR.AA-05 defines and reviews access policies but does not address code-level pathname neutralization, so neither direction prevents CWE-22.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing in development catches path traversal via static/dynamic analysis.

prevents

Secure SDLC mandates input validation and path sanitization that directly prevent path traversal.

prevents

Application security requirements include rules for safe file handling and canonicalization.

prevents

Secure architecture principles require least-privilege file access and directory isolation.

prevents

Secure coding standards explicitly forbid unsafe path construction and mandate safe APIs.

mitigates

Information access restriction limits which files an application may read or write.

References