dbcve.org
SglangApplication · Lmsys

CVE-2026-3059

CRITICAL · 9.8 CVSS v3.1 Published 2026-03-12
Fix available
A fix is available. Upgrade to after 0.5.9 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
SGLang's multimodal generation module is vulnerable to unauthenticated remote code execution through the ZMQ broker, which deserializes untrusted data using pickle.loads() without authentication.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

SGLang's multimodal generation module contains a critical vulnerability in its ZMQ broker component that deserializes untrusted data using pickle.loads() without any authentication mechanism. An unauthenticated attacker can send malicious serialized payloads to achieve remote code execution on the server.

MitigationImplement authentication on the ZMQ broker and replace pickle.loads() with a safer deserialization method (e.g., JSON,msgpack) or a secure pickle alternative with signature verification.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
SglangApplication
Affected:>= 0.5.5, <= 0.5.9

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Sglang version
    Run 'pip show sglang' or 'pip list | grep sglang' to display the installed version
    Affected if The installed version is >= 0.5.5 and <= 0.5.9
  2. Confirm ZMQ broker component is in use
    Inspect running Sglang processes and check for ZMQ-related flags such as --zmq-broker or --enable-zmq-broker in the startup command or configuration file
    Affected if The ZMQ broker component is enabled or configured in the Sglang deployment
  3. Verify ZMQ broker accepts external connections
    Review the ZMQ broker bind address configuration (e.g., inspect configuration files, startup scripts, or running process environment variables for ZMQ_ENDPOINT or similar bind settings)
    Affected if The ZMQ broker is bound to a non-localhost interface or is accessible from untrusted networks
  4. Identify pickle deserialization in ZMQ path
    Search the Sglang installation files for 'pickle.loads' within ZMQ-related modules (look in sglang/python/sglang/srt/conversation.py or similar paths under the sglang installation directory)
    Affected if The code contains pickle.loads() calls being used to deserialize data received by the ZMQ broker without signature verification or authentication checks

You are affected if Sglang version is between 0.5.5 and 0.5.9 inclusive AND the ZMQ broker component is enabled, accepting external connections, and using pickle.loads() for deserialization.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 0.5.9
Vendor patch github.com →
Interim mitigation

Implement authentication on the ZMQ broker and replace pickle.loads() with a safer deserialization method (e.g., JSON,msgpack) or a secure pickle alternative with signature verification.

Recommended fix Moderate confidence

Sglang version > 0.5.9 (e.g., 0.5.10 or later stable release containing the PR #20904 fix)

  1. 1. Identify the current Sglang version in use (e.g., run `pip show sglang` or check requirements.txt)
  2. 2. Upgrade Sglang to a version beyond 0.5.9 that includes the fix from PR #20904 (recommended: upgrade to the latest stable release)
  3. 3. Verify the upgrade was successful: `pip show sglang` and confirm the version is > 0.5.9
  4. 4. Restart all Sglang services to load the updated package
  5. 5. If using ZMQ broker, verify that the broker no longer uses pickle.loads() on unauthenticated data
Caveat Review release notes for any breaking changes between 0.5.x and the target version

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Sglang Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-3059 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data