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CVE Record

CVE-2026-48779: ws: Memory exhaustion DoS from tiny fragments and data chunks

ws is an open source WebSocket client and server for Node.js. All versions from 1.1.0 up to (but not including) 5.2.5, from 6.0.0 up to 6.2.4, from 7.0.0 up to 7.5.11, and from 8.0.0 up to 8.21.0 are affected by a memory exhaustion DoS vulnerability. A peer can send a high volume of exceptionally small fragments and data chunks, with modest network traffic, to force the remote peer into allocating and holding structural wrappers that consume far more memory than the default documented message-size limit, leading to process termination due to OOM. This issue has been fixed in versions 5.2.5, 6.2.4, 7.5.11, and 8.21.0.

HighCVSS 7.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2026-48779 can crash Node.js services that use vulnerable ws WebSocket versions. An untrusted peer can make the process consume excessive memory, causing service outage. The issue is availability-focused, not data theft, but internet-facing real-time services can face business disruption.

Executive priority

Treat as high-priority patching for internet-facing or business-critical WebSocket services. It can cause outages without authentication, but current provided evidence does not show active exploitation or data compromise.

Technical view

The ws package allocates and retains disproportionate wrapper structures when handling many very small fragments and data chunks. A remote peer can trigger memory exhaustion with modest traffic. Affected ranges are ws 1.1.0-<5.2.5, 6.0.0-<6.2.4, 7.0.0-<7.5.11, and 8.0.0-<8.21.0.

Likely exposure

Node.js applications, gateways, developer tools, and downstream products using ws for WebSocket client or server handling are potentially exposed, especially where WebSocket endpoints accept internet or tenant-controlled peers. Exposure may be direct or through transitive npm dependencies.

Exploitation context

The source bundle reports no CISA KEV listing and provides no cited evidence of active exploitation. The CVSS vector indicates remote, low-complexity, unauthenticated exploitation with high availability impact and no confidentiality or integrity impact.

Researcher notes

Key evidence is the GitHub advisory, CVE record, patch commits, and Red Hat downstream advisories. The public bundle identifies fixed versions and CWE resource-exhaustion categories, but does not include proof-of-concept details or confirmed exploitation.

Mitigation direction

  • Upgrade ws to 5.2.5, 6.2.4, 7.5.11, 8.21.0, or later supported releases.
  • Update lockfiles and rebuild deployed artifacts so transitive ws copies are replaced.
  • Check Red Hat errata and CSAF data for affected downstream packages.
  • Prioritize externally reachable WebSocket services and critical real-time workflows.
  • If immediate upgrade is blocked, follow vendor guidance for supported temporary controls.

Validation and detection

  • Inventory direct and transitive ws versions across package manifests, lockfiles, containers, and SBOMs.
  • Confirm deployed runtime artifacts no longer contain affected ws ranges.
  • Map which applications expose WebSocket endpoints to untrusted clients or tenants.
  • Review Red Hat advisories if using packaged Node.js components from Red Hat.
  • Monitor affected services for abnormal memory growth and OOM restarts until remediated.
Prepared
Confidence
high
Sources
12

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

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cwe · low confidence lookup

CWE-1050: Exact CWE lookup

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cwe · low confidence lookup

CWE-400: 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.

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cwe · low confidence lookup

CWE-770: 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.

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cve · low confidence lookup

CVE-2026-48779 mapping review

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

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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:N/I:N/A:H

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
21Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: pocAutomatable: yesTechnical 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:N/I:N/A:H3.93.6GitHub_M
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

7.5High
CVSS 3.1 vector shape for CVE-2026-48779Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

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: Denial of Service via memory exhaustion from small WebSocket fragments
other:Red Hat severity ratingcvssV3_1
  • 2026-06-16T22:01:24.571Z: Reported to Red Hat.
  • 2026-06-16T21:26:22.537Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
websocketsws>= 1.1.0, < 5.2.5, >= 6.0.0, < 6.2.4, >= 7.0.0, < 7.5.11, >= 8.0.0, < 8.21.0Listed
Weakness

CWE details

CWE-1050CWE-400CWE-770

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

CWE-1050 · source CWE mapping

Excessive Platform Resource Consumption within a Loop

Excessive Platform Resource Consumption within a Loop represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs
CWE-400 · source CWE mapping

Uncontrolled Resource Consumption

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

Open CWE intelligenceSame-CWE CVEs
CWE-770 · source CWE mapping

Allocation of Resources Without Limits or Throttling

Allocation of Resources Without Limits or Throttling represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs