What’s Vulnerable › Vulnerabilities

CVE-2025-58183: Unbounded allocation when parsing GNU sparse map in archive/tar

• Severity: medium (CVSS 4.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-10-29 · updated 2026-10-08

Description

tar.Reader does not set a maximum size on the number of sparse region data blocks in GNU tar pax 1.0 sparse files. A maliciously-crafted archive containing a large number of sparse regions can cause a Reader to read an unbounded amount of data from the archive into memory. When reading from a compressed source, a small compressed input can result in large allocations.

Affected products

• Go standard library archive/tar: before 1.24.8; from 1.25.0 before 1.25.2 — fixed in 1.24.8, 1.25.2

How to fix

Upgrade to a fixed version: Go standard library archive/tar 1.24.8, 1.25.2. Check the vendor advisory for mitigations.

References

• https://go.dev/cl/709861
• https://go.dev/issue/75677
• https://groups.google.com/g/golang-announce/c/4Emdl2iQ_bI
• https://pkg.go.dev/vuln/GO-2025-4014
• http://www.openwall.com/lists/oss-security/2025/10/08/1

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