This page tracks the Ubuntu fix status. The vulnerability itself is described on the main CVE page. View CVE-2026-35387 →

UBUNTU-CVE-2026-35387

Vulnerability in openssh (UBUNTU-CVE-2026-35387)

Summary

Vulnerability in openssh (UBUNTU-CVE-2026-35387). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 1:8.9p1-3ubuntu0.15 or later.

Original description

The description as published by the source.

OpenSSH before 10.3 can use unintended ECDSA algorithms. Listing of any ECDSA algorithm in PubkeyAcceptedAlgorithms or HostbasedAcceptedAlgorithms is misinterpreted to mean all ECDSA algorithms.

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-2026-35387 has been found in openssh.
Risk of unauthorized operations or information disclosure.
What to do: upgrade openssh to 1:8.9p1-3ubuntu0.15 or later.
If unsure, ask your IT team or search "openssh UBUNTU-CVE-2026-35387" on the vendor's site.

UBUNTU-CVE-2026-35387 (openssh)
Attack vector: remote (network-reachable) / no user interaction
Patched: 1:8.9p1-3ubuntu0.15 — 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 openssh.

📍 Affected scope

Check the vendor advisory for the affected versions of openssh.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 1:8.9p1-3ubuntu0.15.

🛡️ 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 'openssh' . 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 'openssh' . | 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 openssh 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 openssh to 1:8.9p1-3ubuntu0.15
```
ステージング環境で 1:8.9p1-3ubuntu0.15 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:Pro:14.04:LTS openssh

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:6.6p1-2ubuntu2.13+esm4"}]}]

Ubuntu:Pro:16.04:LTS openssh

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:7.2p2-4ubuntu2.10+esm10"}]}]

Ubuntu:Pro:FIPS:16.04:LTS openssh