CVE-2026-23942: erlang erlang\/otp Path Traversal

CVSS: 5.4v3.1MediumModified

AliasesUBUNTU-CVE-2026-23942DEBIAN-CVE-2026-23942

Published 13-03-2026Last modified 24-07-2026

Vulnerability summary

CVE-2026-23942 is a medium (CVSS 5.4) Path Traversal vulnerability in erlang erlang\/otp. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 30.1% of scored vulnerabilities.

Overall risk

22/100

0100

Low · default modelHow is this calculated?

CVSS score

5.4/10

010

Medium · v3.1 (NVD)

EPSS score

0.38%

0%100%

Low · +0.01 pp in 30 days

KEVNot listedIn no KEV catalog

RansomwareNone recordedNo known use recorded

Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 3 · Related 3

OPENSUSE-SU-2026:10947-1 OPENSUSE-SU-2026:20607-1 USN-8901-1

Timeline

13-03-2026
PublishedVulnerability first disclosed.
24-07-2026
Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

6 scores · 4 sources · 2 versions

v4.05.3v3.15.4

EPSS trend

Probability

0.38%

Chance of exploitation in the next 30 days

Percentile

30%

Versus all other CVEs

30-day change

+0.01 pp

From 0.36% on 19-09-2026

19-09-202619-10-2026

EPSS score

0.38%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

Affected systems

Erlang3 products

erlang\/otp≥ 17.0, < 26.2.5.18 | ≥ 27.0, < 27.3.4.9 | ≥ 28.0, < 28.4.1
erlang\/ssh≥ 3.0.1, < 5.1.4.14 | ≥ 5.2, < 5.2.11.6 | ≥ 5.5, ≤ 5.5.1
otp≥ 3.0.1 (No fix recorded) | ≥ 17.0 (No fix recorded) | ≥ 84adefa331c4159d432d22840663c38f155cd4c1 (No fix recorded)

Debian1 product

erlang< 1:25.2.3+dfsg-1+deb12u4 | < 1:27.3.4.1+dfsg-1+deb13u2 | < 1:27.3.4.9+dfsg-1

Ubuntu1 product

erlang< 1:16.b.3-dfsg-1ubuntu2.2+esm3 | < 1:18.3-dfsg-1ubuntu3.1+esm4 | < 1:20.2.2+dfsg-1ubuntu2+esm4 | < 1:22.2.7+dfsg-1ubuntu0.5+esm3 | < 1:24.2.1+dfsg-1ubuntu0.8 | < 1:25.3.2.8+dfsg-1ubuntu4.8 | All versions (No fix recorded) | < 1:27.3.4.6+dfsg-1ubuntu0.2

3 vendors · 5 products