CVE-2026-109380: Improper Validation of Specified Quantity in Input in ayuhito modern-tar
Description
modern-tar versions 0.3.5 through 0.8.5 have a memory exhaustion vulnerability caused by improper validation of entry sizes during archive extraction. Attackers can craft archives with negative entry sizes via malformed non-octal bytes, leading to indefinite buffering and process memory exhaustion.
CVSS v4.0
Score 8.7high
Affected software
ayuhito
modern-tar
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-109380 affects modern-tar versions 0.3.5 through 0.8.5. The vulnerability arises from the readOctal() function parsing non-octal bytes as negative entry sizes. When a crafted, optionally gzip-compressed archive is processed by unpackTar(), it causes indefinite buffering of chunks, exhausting the process memory and suppressing subsequent archive entries. This improper validation of specified quantity in input leads to a denial-of-service condition via memory exhaustion.
Potential Impact
Successful exploitation results in denial of service by exhausting the memory of the process handling the archive extraction. This can cause the application or system component using modern-tar to become unresponsive or crash, disrupting normal operations.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid processing untrusted or unauthenticated archives with modern-tar versions 0.3.5 through 0.8.5.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-10-12T14:23:25.691Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6acd4b442cdf04f656d3ef5c
Added to database: 10/12/2026, 21:04:04 UTC
Last enriched: 10/12/2026, 21:34:07 UTC
Last updated: 10/12/2026, 21:34:07 UTC
Views: 6
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