Vulnerability in cpio (UBUNTU-CVE-2026-66486)

Summary

Vulnerability in cpio (UBUNTU-CVE-2026-66486). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 2.11+dfsg-1ubuntu1.2+esm3 or later.

Original description

The description as published by the source.

GNU cpio is vulnerable to improper encoding or escaping of output in its archive member listing functionality. When listing archive members via cpio -it, member names are printed directly to output without quoting or escaping. An attacker can craft a cpio archive containing member names with embedded newline characters or ANSI escape sequences, causing forged listing entries or terminal control sequence injection when the listing is displayed. This issue has been fixed in commit 2ff9600c9ef32e88759843cdbde74c8db5ae9b30

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-2026-66486 has been found in cpio.
Risk of unauthorized operations or information disclosure.
What to do: upgrade cpio to 2.11+dfsg-1ubuntu1.2+esm3 or later.
If unsure, ask your IT team or search "cpio UBUNTU-CVE-2026-66486" on the vendor's site.

UBUNTU-CVE-2026-66486 (cpio)
Patched: 2.11+dfsg-1ubuntu1.2+esm3 — 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 cpio.

📍 Affected scope

Check the vendor advisory for the affected versions of cpio.

🔥 Severity

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

🔧 How to fix

Update to 2.11+dfsg-1ubuntu1.2+esm3.

🛡️ 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 'cpio' . 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 'cpio' . | 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 cpio 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 cpio to 2.11+dfsg-1ubuntu1.2+esm3
```
ステージング環境で 2.11+dfsg-1ubuntu1.2+esm3 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 cpio

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.11+dfsg-1ubuntu1.2+esm3"}]}]

Ubuntu:Pro:16.04:LTS cpio

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.11+dfsg-5ubuntu1.1+esm2"}]}]

Ubuntu:Pro:18.04:LTS cpio

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.12+dfsg-6ubuntu0.18.04.4+esm1"}]}]

Ubuntu:Pro:20.04:LTS cpio

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.13+dfsg-2ubuntu0.4+esm1"}]}]

Ubuntu:22.04:LTS cpio

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.13+dfsg-7ubuntu0.2"}]}]

Ubuntu:24.04:LTS cpio

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.15+dfsg-1ubuntu2.1"}]}]

Ubuntu:26.04:LTS cpio

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.15+dfsg-2.1ubuntu0.1"}]}]

References

advisory ubuntu.com
report ubuntu.com
report cve.org
report cert.pl
report git.savannah.gnu.org