Buffer Overflow in Squirrel (CVE-2026-9541)
Summary
Vulnerability in Squirrel (CVE-2026-9541). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
A security flaw has been discovered in Squirrel up to 3.2. Impacted is the function ReadObject of the file squirrel/sqobject.cpp of the component Cnut File Handler. Performing a manipulation results in heap-based buffer overflow. The attack is only possible with local access. The exploit has been released to the public and may be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.
Source: NIST National Vulnerability Database NVD GitHub Advisory
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 CVE-2026-9541 has been found in Squirrel.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Squirrel CVE-2026-9541" on the vendor's site.
CVE-2026-9541 (Squirrel) — CWE-119 / CVSS v3 5.3
Attack vector: local / no user interaction
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 (CWE-119) exists in Squirrel.
Check the vendor advisory for the affected versions of Squirrel.
Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
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 'Squirrel' . 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
-
1Identify exposure identify
grep -r 'Squirrel' . | 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
Squirrelを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-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。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-9541 squirrel3
- Ubuntu UBUNTU-CVE-2026-9541 squirrel3
References
- advisory cna@vuldb.com
- exploit github.com
- exploit cna@vuldb.com
- exploit cna@vuldb.com
- web cna@vuldb.com
- web nvd.nist.gov
- web github.com