CVE-2026-39821 Affecting grafana-mimir-3.0-mimirtool package, versions <3.0.7-r0


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.36% (28th percentile)

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  • Snyk IDSNYK-MINIMOSLATEST-GRAFANAMIMIR30MIMIRTOOL-17274527
  • published10 Jun 2026
  • disclosed22 May 2026

Introduced: 22 May 2026

NewCVE-2026-39821  (opens in a new tab)

How to fix?

Upgrade Minimos:latest grafana-mimir-3.0-mimirtool to version 3.0.7-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream grafana-mimir-3.0-mimirtool package and not the grafana-mimir-3.0-mimirtool package as distributed by Minimos. See How to fix? for Minimos:latest relevant fixed versions and status.

The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-only label. For example, ToUnicode("xn--example-.com") incorrectly returns the name "example.com" rather than an error. This behavior can lead to privilege escalation in programs using the idna package. For example, a program which performs privilege checks on the ASCII hostname may reject "example.com" but permit "xn--example-.com". If that program subsequently converts the ASCII hostname to Unicode, it will inadvertently permits access to the Unicode name "example.com".

CVSS Base Scores

version 3.1