WITHDRAWN
CVE-2026-62389
ws < 8.21.1 Default maxFragments Allows Memory Exhaustion DoS
Description

Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority as a duplicate of CVE-2026-48779.

INFO

Published Date :

July 15, 2026, 6:16 p.m.

Last Modified :

July 29, 2026, 6:16 p.m.

Remotely Exploit :

Affected Products

The following products are affected by CVE-2026-62389 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Websockets_project websockets
1 Ws_project ws
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 HIGH [email protected]
CVSS 3.1 HIGH MITRE-CVE
CVSS 4.0 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 HIGH [email protected]

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-62389 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-62389 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Rejected by [email protected]

    Jul. 29, 2026

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Jul. 29, 2026

    Action Type Old Value New Value
    Changed Description ws before 8.21.1 contains a memory exhaustion vulnerability in lib/receiver.js where the fragment guard only triggers when fragment count reaches maxFragments, allowing attackers to exhaust memory by sending incomplete fragmented WebSocket messages. Attackers can send a text frame with FIN=0 followed by continuation frames without completing the sequence, causing each fragment to be stored as a separate Buffer object with significant overhead, enabling denial of service through heap exhaustion. Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority as a duplicate of CVE-2026-48779.
    Removed CVSS V4.0 VulnCheck: AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Removed CVSS V3.1 VulnCheck: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
    Removed CWE VulnCheck: CWE-770
    Removed Reference VulnCheck: https://github.com/websockets/ws/commit/f197ac65140920bdcecdab74bfc69c2d7858e55d
    Removed Reference VulnCheck: https://github.com/websockets/ws/issues/2331
    Removed Reference VulnCheck: https://github.com/websockets/ws/releases/tag/8.21.1
    Removed Reference VulnCheck: https://www.vulncheck.com/advisories/ws-default-maxfragments-allows-memory-exhaustion-dos
    Removed Affected [{'repo': 'https://github.com/websockets/ws', 'vendor': 'websockets', 'product': 'ws', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '8.21.1', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/ws', 'defaultStatus': 'unaffected'}]
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 15, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-62389', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-15T17:55:24.792464Z'}
  • New CVE Received by [email protected]

    Jul. 15, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://github.com/websockets/ws', 'vendor': 'websockets', 'product': 'ws', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '8.21.1', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/ws', 'defaultStatus': 'unaffected'}]
    Added Description ws before 8.21.1 contains a memory exhaustion vulnerability in lib/receiver.js where the fragment guard only triggers when fragment count reaches maxFragments, allowing attackers to exhaust memory by sending incomplete fragmented WebSocket messages. Attackers can send a text frame with FIN=0 followed by continuation frames without completing the sequence, causing each fragment to be stored as a separate Buffer object with significant overhead, enabling denial of service through heap exhaustion.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
    Added CWE CWE-770
    Added Reference https://github.com/websockets/ws/commit/f197ac65140920bdcecdab74bfc69c2d7858e55d
    Added Reference https://github.com/websockets/ws/issues/2331
    Added Reference https://github.com/websockets/ws/releases/tag/8.21.1
    Added Reference https://www.vulncheck.com/advisories/ws-default-maxfragments-allows-memory-exhaustion-dos
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.