Process-memory disclosure via interrupted buffer zeroing
Published Jan 20, 2026 · Updated Jan 20, 2026
Uninitialized-memory exposure in Node.js 20.19.6 and other affected releases allows attackers to read process data via timed vm execution. The vm timeout path can interrupt allocation while Node.js has disabled zero filling, leaving Buffer.alloc and TypedArray backing memory populated with bytes from earlier in-process operations. Exploitation requires precise timing and in-process code execution unless untrusted workload controls vm execution and its timeout; exposure is limited to residual process memory, while incomplete initialization can also corrupt data.
Summary
What happened
Uninitialized-memory exposure in Node.js 20.19.6 and other affected releases allows attackers to read process data via timed vm execution. The vm timeout path can interrupt allocation while Node.js has disabled zero filling, leaving Buffer.alloc and TypedArray backing memory populated with bytes from earlier in-process operations. Exploitation requires precise timing and in-process code execution unless untrusted workload controls vm execution and its timeout; exposure is limited to residual process memory, while incomplete initialization can also corrupt data.
The record
- CVE
- CVE-2025-55131
- Published
- Jan 20, 2026
- Updated
- Jan 20, 2026
- Vendor
- Node.js
- Product
- Node.js
- Classifications
- T1005
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 20, 2026CVE publishedPublication date reported by the CVE source.
- Jan 20, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0 <10.*
- Affected versionversion=11.0 <11.*
- Affected versionversion=12.0 <12.*
- Affected versionversion=13.0 <13.*
- Affected versionversion=14.0 <14.*
- Affected versionversion=15.0 <15.*
- Affected versionversion=16.0 <16.*
- Affected versionversion=17.0 <17.*
- Affected versionversion=18.0 <18.*
- Affected versionversion=20.19.6 <=20.19.6
- Affected versionversion=22.21.1 <=22.21.1
- Affected versionversion=24.12.0 <=24.12.0
- Affected versionversion=25.2.1 <=25.2.1
- Affected versionversion=4.0 <4.*
- Affected versionversion=5.0 <5.*
- Affected versionversion=6.0 <6.*
- Affected versionversion=7.0 <7.*
- Affected versionversion=8.0 <8.*
- Affected versionversion=9.0 <9.*
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo