CVE-2026-59874: CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop') in isaacs node-tar
node-tar is a tar archive manipulation library for Node.js. Prior to 7.5.18, tar.replace accepts a checksum-valid tar header with a negative base-256 encoded entry size, causing the archive scanner to make no progress while repeatedly parsing the same header. This issue is fixed in version 7.5.18.
AI Analysis
Technical Summary
The vulnerability CVE-2026-59874 affects the isaacs node-tar library, a Node.js tar archive manipulation tool. Versions before 7.5.18 allow the tar.replace function to process a tar header that is checksum-valid but contains a negative base-256 encoded entry size. This malformed header causes the archive scanner to loop infinitely, as it repeatedly parses the same header without advancing. This is classified as CWE-835 (Loop with Unreachable Exit Condition). The issue is resolved in version 7.5.18.
Potential Impact
An attacker can craft a malicious tar archive that triggers an infinite loop during processing by node-tar versions prior to 7.5.18. This can cause denial of service by making the application hang or become unresponsive when handling such archives. There is no indication of privilege escalation, code execution, or data corruption beyond denial of service.
Mitigation Recommendations
Upgrade node-tar to version 7.5.18 or later, where this vulnerability is fixed. Since the vendor advisory does not specify any temporary or alternative mitigations, applying the official fix is the recommended action. Patch status is confirmed fixed in 7.5.18.
CVE-2026-59874: CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop') in isaacs node-tar
Description
node-tar is a tar archive manipulation library for Node.js. Prior to 7.5.18, tar.replace accepts a checksum-valid tar header with a negative base-256 encoded entry size, causing the archive scanner to make no progress while repeatedly parsing the same header. This issue is fixed in version 7.5.18.
CVSS v4.0
Score 8.7high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-59874 affects the isaacs node-tar library, a Node.js tar archive manipulation tool. Versions before 7.5.18 allow the tar.replace function to process a tar header that is checksum-valid but contains a negative base-256 encoded entry size. This malformed header causes the archive scanner to loop infinitely, as it repeatedly parses the same header without advancing. This is classified as CWE-835 (Loop with Unreachable Exit Condition). The issue is resolved in version 7.5.18.
Potential Impact
An attacker can craft a malicious tar archive that triggers an infinite loop during processing by node-tar versions prior to 7.5.18. This can cause denial of service by making the application hang or become unresponsive when handling such archives. There is no indication of privilege escalation, code execution, or data corruption beyond denial of service.
Mitigation Recommendations
Upgrade node-tar to version 7.5.18 or later, where this vulnerability is fixed. Since the vendor advisory does not specify any temporary or alternative mitigations, applying the official fix is the recommended action. Patch status is confirmed fixed in 7.5.18.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-07-07T15:41:53.607Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4e73c2c9d9e3dbe36042ca
Added to database: 07/08/2026, 15:58:58 UTC
Last enriched: 07/08/2026, 16:13:22 UTC
Last updated: 08/22/2026, 10:52:10 UTC
Views: 99
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