CrossbeamApplication · Crossbeam Project

CVE-2018-20996

CRITICAL · 9.8 CVSS v3.0 Published 2019-08-26
Fix available
A fix is available. Upgrade to 0.4.1 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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
An issue was discovered in the crossbeam crate before 0.4.1 for Rust. There is a double free because of destructor mishandling.

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

A double free vulnerability exists in the crossbeam Rust crate before version 0.4.1, caused by improper destructor handling. This memory safety flaw could allow attackers to corrupt memory and potentially achieve arbitrary code execution.

MitigationUpgrade the crossbeam dependency to version 0.4.1 or later in Cargo.toml and verify compatibility through testing.

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
CrossbeamApplication
Affected:< 0.4.1

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:3.0/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. Locate Cargo.toml
    Find the Cargo.toml file in your project root that declares dependencies
    Affected if crossbeam is listed as a dependency
  2. Check crossbeam version declaration
    In Cargo.toml, look for crossbeam under [dependencies] or [dev-dependencies] and note the specified version (e.g., crossbeam = "0.4.0" or crossbeam = "0.4")
    Affected if Any crossbeam version constraint that resolves to less than 0.4.1
  3. Check resolved version in Cargo.lock
    Open Cargo.lock and search for the [[package]] entry with name = "crossbeam", then read the version field (e.g., version = "0.4.0")
    Affected if The version field shows 0.4.0 or any version below 0.4.1
  4. Query installed crate version
    Run `cargo tree -p crossbeam` or `cargo list --depth=1 | grep crossbeam` to see the actual crossbeam version being used in the build
    Affected if The reported version is 0.4.0 or lower

You are affected if the crossbeam crate version resolved and used in your build is any version prior to 0.4.1.

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 0.4.1 or later
Fixed in 0.4.1
Interim mitigation

Upgrade the crossbeam dependency to version 0.4.1 or later in Cargo.toml and verify compatibility through testing.

Recommended fix High confidence

crossbeam 0.4.1

  1. Update the crossbeam dependency in your Cargo.toml file to version 0.4.1 or later (e.g., crossbeam = "0.4.1")
  2. Run `cargo update` to update the Cargo.lock file
  3. Run `cargo build` or `cargo test` to verify the application compiles and tests pass with the updated dependency

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

Fix this in Crossbeam Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,752.

Scan for this in your stack

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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-2018-20996 in production — separate from our analysis above.

No notes yet

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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