Information Disclosure in Erlangotp (CVE-2026-48855)
Summary
Vulnerability in Erlangotp (CVE-2026-48855). Confidential information can be exposed externally.
Original description
The description as published by the source.
Summary
Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Erlang OTP ssh (ssh_sftpd module) allows File Discovery.
The SSH_FXP_READLINK handler in ssh_sftpd sends the raw result of file:read_link/2 to the client without calling chroot_filename/2 to strip the backend root prefix. An authenticated SFTP client can create a symlink inside the chroot pointing to /; ssh_sftpd resolves the target to the absolute backend root and stores it on disk. Reading the symlink back via SSH_FXP_READLINK returns that absolute path, for example /data/sftp, instead of the chrooted value /.
The information disclosed is the absolute filesystem path of the SFTP root directory and of any symlink targets within it. No file contents, credentials, or access to paths outside the root directory are obtainable through this issue alone.
This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl.
This issue affects OTP from OTP 17.0 before 29.0.2, 28.5.0.2 and 27.3.4.13 corresponding to ssh from 3.0.1 before 6.0.1, 5.5.2.1 and 5.2.11.8.
Workaround
* Use OS-level chroot to run the Erlang VM/SFTP server process in an isolated filesystem environment, eliminating reliance on the application-level root option.
* Ensure that the SFTP server port is not reachable from untrusted machines.
* Ensure that no sensitive information (usernames, project names, mount topology) is inferrable from the absolute path of the configured root directory.
Con…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-48855 has been found in Erlangotp.
Confidential information can be exposed externally. CVSS score: 6.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Erlangotp CVE-2026-48855" on the vendor's site.
CVE-2026-48855 (Erlangotp) — CWE-200 / CVSS v3 6.5
Attack vector: remote (network-reachable) / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Information disclosure (CWE-200) exists in Erlangotp.
Check the vendor advisory for the affected versions of Erlangotp.
Severity: Medium (CVSS 6.5/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Erlangotp' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'Erlangotp' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Erlangotpを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-48855 erlang
- Ubuntu UBUNTU-CVE-2026-48855 erlang Fixed in: 1:16.b.3-dfsg-1ubuntu2.2+esm3
References
- advisory cna.erlef.org
- advisory osv.dev
- patch github.com
- patch github.com
- web erlang.org
- web github.com