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CVE Record

CVE-2026-45736: ws: Uninitialized memory disclosure

ws is an open source WebSocket client and server for Node.js. Prior to 8.20.1, the websocket.close() implementation is vulnerable to uninitialized memory disclosure when a TypedArray is passed as the reason argument. This vulnerability is fixed in 8.20.1.

HighCVSS 7.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This flaw can let a remote, unauthenticated actor cause ws to disclose memory contents during WebSocket close handling. The known affected package is the Node.js ws library before 8.20.1. Business urgency is high where ws is internet-facing or embedded in products handling sensitive data.

Executive priority

Treat as high priority for externally reachable Node.js services because the impact is data exposure, not service disruption. Patch quickly, but avoid claiming emergency exploitation unless new evidence appears outside this bundle.

Technical view

CVE-2026-45736 affects ws >=8.0.0 and <8.20.1. websocket.close() can disclose uninitialized memory when a TypedArray is passed as the reason argument. The issue maps to CWE-824 and CWE-908 and has CVSS 7.5 for network-reachable confidentiality impact only.

Likely exposure

Exposure is likely in Node.js services, frameworks, or bundled products using ws versions 8.0.0 through 8.20.0. The bundle does not identify other affected products beyond websockets/ws and listed Red Hat advisories.

Exploitation context

The CVSS vector indicates remote, low-complexity, unauthenticated exploitation with no user interaction. The bundle marks KEV false and provides no evidence of active exploitation, public exploit code, or weaponized campaigns.

Researcher notes

The vulnerable condition is specifically TypedArray handling in websocket.close() reason processing. Analysis should focus on dependency reachability and whether application-controlled input can influence close reasons. Do not broaden affected scope beyond ws without vendor evidence.

Mitigation direction

  • Upgrade ws to version 8.20.1 or later.
  • Identify transitive dependencies that bundle vulnerable ws versions.
  • Apply relevant Red Hat errata where Red Hat packages embed ws.
  • Prioritize internet-facing WebSocket services handling sensitive data.
  • Check vendor guidance for products that redistribute ws.

Validation and detection

  • Inventory package-lock, npm-shrinkwrap, pnpm-lock, yarn.lock, and SBOM entries for ws.
  • Confirm deployed artifacts resolve ws to 8.20.1 or later.
  • Review container and platform images for bundled vulnerable ws versions.
  • Map exposed WebSocket routes to applications using ws.
  • Track remediation against listed Red Hat advisories where applicable.
Prepared
Confidence
high
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-824: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cwe · low confidence lookup

CWE-908: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-45736 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
High
CVSS
7.5 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
16Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: pocAutomatable: noTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N3.93.6redhat-SADP
4.4CVSS 3.1MediumCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N0.73.6GitHub_M

Vulnerability scoring details

Base CVSS 3.1 score

7.5High
CVSS 3.1 vector shape for CVE-2026-45736Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPws: ws: Uninitialized memory disclosure via `websocket.close()` with `TypedArray`
other:Red Hat severity ratingcvssV3_1
  • 2026-05-15T16:00:55.786Z: Reported to Red Hat.
  • 2026-05-15T14:53:57.263Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
websocketsws>= 8.0.0, < 8.20.1Listed
Weakness

CWE details

CWE-824CWE-908

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-824 · source CWE mapping

Access of Uninitialized Pointer

Access of Uninitialized Pointer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs
CWE-908 · source CWE mapping

Use of Uninitialized Resource

Use of Uninitialized Resource represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs