Vulnerability in libssh (UBUNTU-CVE-2026-15370)

Summary

Vulnerability in libssh (UBUNTU-CVE-2026-15370). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 0.11.3-1ubuntu2.1 or later.

Original description

The description as published by the source.

A flaw was found in libssh. During SFTP server directory listing, the longname field is constructed with unsafe concatenation into a fixed-size stack buffer. When a client causes the server to list attacker-controlled filenames, sufficiently long names can overflow that stack buffer and may lead to crashes or possible code execution on the server.

Source: OSV.dev (Open Source Vulnerabilities) OSV

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 UBUNTU-CVE-2026-15370 has been found in libssh.
Successful exploitation can lead to full system takeover.
What to do: upgrade libssh to 0.11.3-1ubuntu2.1 or later.
If unsure, ask your IT team or search "libssh UBUNTU-CVE-2026-15370" on the vendor's site.

UBUNTU-CVE-2026-15370 (libssh)
Attack vector: local
Patched: 0.11.3-1ubuntu2.1 — apply immediately
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.

❓ What is the problem

A vulnerability (unclassified) exists in libssh.

📍 Affected scope

Check the vendor advisory for the affected versions of libssh.

🔥 Severity

Severity: ?. Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to 0.11.3-1ubuntu2.1.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'libssh' . 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

1
Identify exposure identify
```
grep -r 'libssh' . | 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 libssh を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade libssh to 0.11.3-1ubuntu2.1
```
ステージング環境で 0.11.3-1ubuntu2.1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
Post-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。

Affected packages

Ubuntu:26.04:LTS libssh

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.11.3-1ubuntu2.1"}]}]

References

advisory ubuntu.com
report ubuntu.com
report cve.org
report libssh.org
report libssh.org