Unsafe Deserialization in sglang (CVE-2026-3989)
Summary
Vulnerability in sglang (CVE-2026-3989). Successful exploitation can lead to full system takeover. Exploitable via replay_request_dump.py. Mitigation: upgrade to 0.5.10 or later.
Original description
The description as published by the source.
SGLangs replay_request_dump.py contains an insecure pickle.load() without validation and proper deserialization. An attacker can take advantage of this by providing a malicious .pkl file, which will execute the attackers code on the device running the script.
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-2026-3989 has been found in sglang.
Attackers can target a specific entry point like replay_request_dump.py over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 7.8/10.
What to do: upgrade sglang to 0.5.10 or later.
If unsure, ask your IT team or search "sglang CVE-2026-3989" on the vendor's site.
CVE-2026-3989 (sglang) — CWE-502 / CVSS v3 7.8
Attack vector: local / unauthenticated
Attack surface: replay_request_dump.py
Patched: 0.5.10 — 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.
Unsafe deserialization (CWE-502) exists in sglang. Attackers reach the vulnerable code path via replay_request_dump.py without authentication.
Check the vendor advisory for the affected versions of sglang. Attack surface: replay_request_dump.py.
Severity: High (CVSS 7.8/10). Successful exploitation can lead to full system takeover.
Update to 0.5.10.
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 'sglang' . 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 'sglang' . | 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
sglang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 sglang to 0.5.10ステージング環境で 0.5.10 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 nvd.nist.gov
- advisory github.com
- package github.com
- patch github.com
- web github.com
- web github.com
- web orca.security
- web orca.security