Vulnerability in perl (UBUNTU-CVE-2026-42496)
Summary
Vulnerability in perl (UBUNTU-CVE-2026-42496). Confidential information can be exposed externally. Mitigation: upgrade to 5.18.2-2ubuntu1.7+esm7 or later.
Original description
The description as published by the source.
Archive::Tar versions before 3.08 for Perl extract symlinks with attacker controlled targets outside the extraction directory. _make_special_file() passes the tar header's linkname to symlink() without validating it against absolute paths or .. segments. The secure-extract mode check that guards regular file extraction does not cover the symlink target. A subsequent open through the extracted name reads or writes the attacker chosen path.
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-2026-42496 has been found in perl.
Confidential information can be exposed externally.
What to do: upgrade perl to 5.18.2-2ubuntu1.7+esm7 or later.
If unsure, ask your IT team or search "perl UBUNTU-CVE-2026-42496" on the vendor's site.
UBUNTU-CVE-2026-42496 (perl)
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 5.18.2-2ubuntu1.7+esm7 — 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.
A vulnerability (unclassified) exists in perl.
Check the vendor advisory for the affected versions of perl.
Severity: ?. Confidential information can be exposed externally.
Update to 5.18.2-2ubuntu1.7+esm7.
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 'perl' . 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
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1Identify exposure identify
grep -r 'perl' . | 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
perlを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade perl to 5.18.2-2ubuntu1.7+esm7ステージング環境で 5.18.2-2ubuntu1.7+esm7 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。
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3Post-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
References
- advisory ubuntu.com
- report ubuntu.com
- report cve.org
- report lists.security.metacpan.org
- report github.com
- report metacpan.org
- report cve.org