CVE-2023-26103 - CVE House
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Status published Medium CVE-2023-26103

Versions of the package deno before 1.31.0 are vulnerable to...

Vulnerability Description

Versions of the package deno before 1.31.0 are vulnerable to Regular Expression Denial of Service (ReDoS) due to the upgradeWebSocket function, which contains regexes in the form of /s*,s*/, used for splitting the Connection/Upgrade header. A specially crafted Connection/Upgrade header can be used to significantly slow down a web socket server.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • Alessio Della Libera
  • Snyk

References

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Affected Vendor

Affected Software

deno
Vulnerable Versions:
0

Timeline

Official Publish: February 25th, 2023
Last Modified: March 11th, 2025
Added to House: July 22nd, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Weaknesses (CWE)

CWE-1333

MITRE ATT&CK TTPs

T1499 Endpoint Denial of Service
Impact
T1190 Exploit Public-Facing Application
Initial Access
T1496 Resource Hijacking
Impact
T1562 Impair Defenses
Defense Evasion
T1070 Indicator Removal on Host
Defense Evasion