CVE-2026-1528
March 12, 2026
ImpactA server can reply with a WebSocket frame using the 64-bit length form and an extremely large length. undici's ByteParser overflows internal math, ends up in an invalid state, and throws a fatal TypeError that terminates the process.
Patches
Patched in the undici version v7.24.0 and v6.24.0. Users should upgrade to this version or later.
Affected Packages
undici (NPM):
Affected version(s) >=7.0.0 <7.24.0Fix Suggestion:
Update to version 7.24.0undici (NPM):
Affected version(s) >=6.0.0 <6.24.0Fix Suggestion:
Update to version 6.24.0undici (NPM):
Affected version(s) >=6.0.0 <6.24.0Fix Suggestion:
Update to version 6.24.0undici (NPM):
Affected version(s) >=6.0.0 <6.24.0Fix Suggestion:
Update to version 6.24.0undici (NPM):
Affected version(s) >=7.0.0 <7.24.0Fix Suggestion:
Update to version 7.24.0undici (NPM):
Affected version(s) >=6.0.0 <6.24.0Fix Suggestion:
Update to version 6.24.0undici (NPM):
Affected version(s) >=7.0.0 <7.24.0Fix Suggestion:
Update to version 7.24.0undici (NPM):
Affected version(s) >=6.0.0 <6.24.0Fix Suggestion:
Update to version 6.24.0undici (NPM):
Affected version(s) >=7.0.0 <7.24.0Fix Suggestion:
Update to version 7.24.0Related Resources (5)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
EPSS
Base Score:
0.07
