CVE-2025-64118Public exploit

Process-memory disclosure via truncated synchronous archive read

Published Oct 30, 2025 · Updated Oct 30, 2025

Information disclosure in isaacs tar 7.5.1 allows local users to read process memory by truncating a synchronously listed archive. In listFileSync, Buffer.allocUnsafe reserves the stat-reported size, but fs.readSync can fill less after truncation and the parser receives the entire buffer. Exploitation requires Node.js 22 or 25.1 and later, sync:true, onReadEntry body handling, and a boundary-timed truncation; larger archives instead hang.

CVSS severity6.1
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in isaacs tar 7.5.1 allows local users to read process memory by truncating a synchronously listed archive. In listFileSync, Buffer.allocUnsafe reserves the stat-reported size, but fs.readSync can fill less after truncation and the parser receives the entire buffer. Exploitation requires Node.js 22 or 25.1 and later, sync:true, onReadEntry body handling, and a boundary-timed truncation; larger archives instead hang.

The record

CVE
CVE-2025-64118
Published
Oct 30, 2025
Updated
Oct 30, 2025
Vendor
isaacs
Product
tar
Classifications
CWE-362, CWE-367, T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 30, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 30, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion== 7.5.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

isaacs · tarversion== 7.5.1

Published CVSS scores

6.1GitHub, Inc.CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:P/VC:H/VI:L/VA:L/SC:H/SI:H/SA:H

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
T1005Data from Local System

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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