CVE-2025-61728: Excessive CPU consumption when building archive index in archive/zip

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-01-28 · updated 2026-06-17
Weakness: CWE-770

Description

archive/zip uses a super-linear file name indexing algorithm that is invoked the first time a file in an archive is opened. This can lead to a denial of service when consuming a maliciously constructed ZIP archive.

Affected products

Go: before 1.24.12; from 1.25.0 before 1.25.6 — fixed in 1.24.12, 1.25.6

How to fix

Upgrade to a fixed version: Go 1.24.12, 1.25.6. Check the vendor advisory for mitigations.

References

https://go.dev/cl/736713
https://go.dev/issue/77102
https://groups.google.com/g/golang-announce/c/Vd2tYVM8eUc
https://pkg.go.dev/vuln/GO-2026-4342
http://www.openwall.com/lists/oss-security/2026/01/15/4

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