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CVE-2026-50635
high
CVSS 8.8
Vulnerability in limesurvey/limesurvey (CVE-2026-50635)
Summary
vulnerability in limesurvey/limesurvey (CVE-2026-50635). Successful exploitation can lead to full system takeover. Exploitable via `Host header`.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-50635** has been found in limesurvey/limesurvey.
Attackers can target a specific entry point like `Host header` over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 8.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "limesurvey/limesurvey CVE-2026-50635" on the vendor's site.
CVE-2026-50635 (limesurvey/limesurvey) — CWE-640 / CVSS v3 8.8
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: Host header
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** (CWE-640) exists in limesurvey/limesurvey. Attackers reach the vulnerable code path via `Host header` without authentication.
📍 Affected scope
limesurvey/limesurvey — . Attack surface: Host header.
🔥 Severity
Severity: High (CVSS 8.8/10). Successful exploitation can lead to full system takeover
🔧 How to fix
Update to the patched release per vendor advisory.
🛡️ 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 'limesurvey/limesurvey' .` against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response Actions (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'limesurvey/limesurvey' . | 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 `limesurvey/limesurvey` を grep し、稼働しているサービス・バージョンを把握する。
-
7Post-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 Step 3 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
composer
limesurvey/limesurvey
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
References
- web https://github.com/LimeSurvey/LimeSurvey/pull/5032
- web [email protected]
- web https://www.vulncheck.com/advisories/limesurvey-password-reset-host-header-injection-discloses-reset-token
- web https://nvd.nist.gov/vuln/detail/CVE-2026-50635
- web https://www.limesurvey.org
- web https://github.com/advisories/GHSA-5c37-5j7w-8mh8
- web https://github.com/LimeSurvey/LimeSurvey/commit/ac2a4f1673de7b56e7a342c338f36e8bb077d4b3
- web https://github.com/LimeSurvey/LimeSurvey/commit/b394cb64328aa6db95e3304f82c8c9e603e9ceb0