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CVE-2026-123866
Published:November 11, 2026
Updated:November 12, 2026
A use-after-free in Node.js HTTP/2 stream teardown can leak response memory, including the contents of other connections' response buffers, to a peer. When a stream is torn down while a write is still backpressured, for example by a peer RST_STREAM or by the server's own per-stream timeout destroying the stream, the stream's response buffer is freed but a reference to it is still used, so freed or unrelated heap memory is written to the socket instead of the intended response. On Node.js 26.x and 24.x the teardown can be driven purely by a remote peer once the window-size change from 26.9.0 and 24.22.0 is present, and on all supported lines the same defect is reachable through an application-initiated teardown such as a per-stream idle timeout. This vulnerability affects Node.js 26.x, 24.x, and 22.x.
Affected Packages
nodejs (CONDA):
Affected version(s) >=22.3.0 <22.23.5
Fix Suggestion:
Update to version 22.23.5
nodejs (CONDA):
Affected version(s) >=24.3.0 <24.22.3
Fix Suggestion:
Update to version 24.22.3
nodejs (CONDA):
Affected version(s) >=26.0.0 <26.13.1
Fix Suggestion:
Update to version 26.13.1
https://github.com/nodejs/node.git (GITHUB):
Affected version(s) >=v24.0.0 <v24.22.3
Fix Suggestion:
Update to version v24.22.3
https://github.com/nodejs/node.git (GITHUB):
Affected version(s) >=v22.0.0 <v22.23.5
Fix Suggestion:
Update to version v22.23.5
https://github.com/nodejs/node.git (GITHUB):
Affected version(s) >=v26.0.0 <v26.13.1
Fix Suggestion:
Update to version v26.13.1
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CVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
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
HIGH
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
Use After Free
EPSS
Base Score:
0.48