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Advisory record · GHSA-63m5-974w-448v

Fleet has a JWT signature bypass vulnerability in Azure AD MDM enrollment

CVSS 9.3 CriticalCriticalEPSS 0.0025 · 17th percentile

Critical, because:

  • CVSS score 9.3: 9.0 or more.

How we decide what’s critical

Published by the GitHub Advisory Database at 20 Jan 2026, 20:55 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
github.com/fleetdm/fleetGo>=4.78.0, <4.78.3 || >=4.77.0, <4.77.1 || >=4.76.0, <4.76.2 || >=4.75.0, <4.75.2 || <4.43.5-0.20260112202845-e225ef57912c4.78.3, 4.77.1, 4.76.2, 4.75.2, 4.43.5-0.20260112202845-e225ef57912c
Identifiers
GHSA-63m5-974w-448v · CVE-2026-23518 · GO-2026-4335
Weakness (CWE)
CWE-347
Tags
Published
20 Jan 2026
Updated
28 Feb 2026

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

ScoreRatingCVSSVectorSource
9.3 Critical 4.0 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N CNA (GitHub_M)
  • CISA KEV Not listed.
  • EPSS 0.0025, the 17th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

This record came from the full history of the GitHub Advisory Database, published 20 Jan 2026. New records show when each source confirmed them.

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.