CVE-2026-23942
What it is
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Erlang OTP (ssh_sftpd module) allows Path Traversal. This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl and program routines ssh_sftpd:is_within_root/2. The SFTP server uses string prefix matching via lists:prefix/2 rather than proper path component validation when checking if a path is within the configured root directory. This allows authenticated users to access sibling directories that share a common name prefix with the configured root directory. For example, if root is set to /home/user1, paths like /home/user10 or /home/user1_backup would incorrectly be considered within the root. This issue affects OTP from OTP 17.0 before OTP 28.4.1, OTP 27.3.4.9 and OTP 26.2.5.18, corresponding to ssh from 3.0.1 before 5.5.1, 5.2.11.6 and 5.1.4.14.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account. Limited direct impact.
- Exploit odds
- 0.4% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.4% in the next 30 days (EPSS).
- Severity: 5.3 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.4% · EPSS, next 30 days
- Weakness
- CWE-22 · Path traversal
- Record status
- Modified
Affected
- Erlang erlang\/otp < 26.2.5.18
- Erlang erlang\/otp < 27.3.4.9
- Erlang erlang\/otp < 28.4.1
- Erlang erlang\/ssh < 5.1.4.14
- Erlang erlang\/ssh < 5.2.11.6
- Erlang erlang\/ssh ≤ 5.5.1
Attack profile CVSS 4.0 · 5.3
- Attack vector
- Network
- Complexity
- Low
- Attack requirements
- None
- Privileges needed
- Low
- User interaction
- None
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/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
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-23942.md and follow it. Check whether this project is affected by CVE-2026-23942. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://cna.erlef.org/cves/CVE-2026-23942.html
- https://github.com/erlang/otp/commit/27688a824f753d4c16371dc70e88753fb410590b
- https://github.com/erlang/otp/commit/5ed603a1211b83b8be2d1fc06d3f3bf30c3c9759
- https://github.com/erlang/otp/commit/9e0ac85d3485e7898e0da88a14be0ee2310a3b28
- https://github.com/erlang/otp/security/advisories/GHSA-4749-w85x-hw9h
- https://osv.dev/vulnerability/EEF-CVE-2026-23942
References
- https://cna.erlef.org/cves/CVE-2026-23942.html
- https://github.com/erlang/otp/commit/27688a824f753d4c16371dc70e88753fb410590b
- https://github.com/erlang/otp/commit/5ed603a1211b83b8be2d1fc06d3f3bf30c3c9759
- https://github.com/erlang/otp/commit/9e0ac85d3485e7898e0da88a14be0ee2310a3b28
- https://github.com/erlang/otp/security/advisories/GHSA-4749-w85x-hw9h
- https://osv.dev/vulnerability/EEF-CVE-2026-23942
- https://www.erlang.org/doc/system/versions.html#order-of-versions