Vulnerability in clamav (UBUNTU-CVE-2026-20215)

Summary

Vulnerability in clamav (UBUNTU-CVE-2026-20215). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 1.5.3+dfsg-0ubuntu0.22.04.2 or later.

Original description

The description as published by the source.

A vulnerability in the 7z file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device. This vulnerability is due to improper boundary checks for content in 7z files during scanning, which may result in an out-of-bounds buffer write. An attacker could exploit this vulnerability by submitting a crafted file that contains 7z content to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software.

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-2026-20215 has been found in clamav.
Risk of unauthorized operations or information disclosure.
What to do: upgrade clamav to 1.5.3+dfsg-0ubuntu0.22.04.2 or later.
If unsure, ask your IT team or search "clamav UBUNTU-CVE-2026-20215" on the vendor's site.

UBUNTU-CVE-2026-20215 (clamav)
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 1.5.3+dfsg-0ubuntu0.22.04.2 — 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 clamav.

📍 Affected scope

Check the vendor advisory for the affected versions of clamav.

🔥 Severity

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

🔧 How to fix

Update to 1.5.3+dfsg-0ubuntu0.22.04.2.

🛡️ 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 'clamav' . 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 'clamav' . | 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 clamav 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 clamav to 1.5.3+dfsg-0ubuntu0.22.04.2
```
ステージング環境で 1.5.3+dfsg-0ubuntu0.22.04.2 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。