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No exploitation reportedFix available

CVE-2026-21226

No exploitation reported by the sources we read.

  • Published2026-01-13
  • Fixed in1.38.0
  • WeaknessCWE-502

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Deserialization of untrusted data in Azure Core shared client library for Python allows an authorized attacker to execute code over a network.

Timeline

dates in UTC
  1. 2026-01-1319:16CVE publishedNVD

Versions per branch

NVD · OSV
Microsoft azure core shared client library
BranchAffectedFixed in
1.x≥ 1.1.0, < 1.38.01.38.0
1.38< 1.38.01.38.0

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As microsoft, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • Microsoft Azure Core shared client library for Python
    Affected
    • ≥ 1.1.0, < 1.38.0fixed in 1.38.0custom

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-07-30

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • airflow-2CleanStartall versions · fixed in 2.10.3-r2
  • airflow-3CleanStartall versions · fixed in 3.0.6-r1
  • azure-cliSUSE:Linux Enterprise Module for Public Cloud 15 SP7all versions · fixed in 2.82.0-150400.14.23.1
  • azure-cliSUSE:Linux Enterprise Module for Public Cloud 15 SP6all versions · fixed in 2.82.0-150400.14.23.1
  • azure-cliSUSE:Linux Enterprise Module for Public Cloud 15 SP5all versions · fixed in 2.82.0-150400.14.23.1
  • azure-cliSUSE:Linux Enterprise Module for Public Cloud 15 SP4all versions · fixed in 2.82.0-150400.14.23.1
  • azure-cli-coreSUSE:Linux Enterprise Module for Public Cloud 15 SP7all versions · fixed in 2.82.0-150400.14.14.1
  • azure-cli-coreSUSE:Linux Enterprise Module for Public Cloud 15 SP6all versions · fixed in 2.82.0-150400.14.14.1

660 more package ranges on OSV.dev

Vendor advisories

  • CVE-2026-21226 Red Hat Product Security26 known affected

    azure-core: Azure Core shared client library for Python Remote Code Execution Vulnerability

    openshift-sandboxed-containers/osc-podvm-builder-rhel9 as a component of Confidential Compute Attestation · workload-availability/fence-agents-remediation-rhel9-operator as a component of Fence Agents Remediation Operator · rhmtc/openshift-migration-hook-runner-rhel8 as a component of Migration Toolkit for Containers · +23 more

Full record on NVD

Fix

  1. Update Microsoft azure core shared client library to 1.38.0
  2. Workaround from the vendor Red Hat Product Security CVE-2026-21226 · 26 productsNo code-level mitigation is provided by Red Hat. Exploitation requires an authorized actor to supply crafted serialized data to an Azure deserialization code path. Until an execution environment shipping azure-core 1.38.0 or later is available, limit which users can create and run Azure-related aut…
  3. No fix available, says the vendor Red Hat Product Security CVE-2026-21226 · 6 productsFix deferred
  4. No fix available, says the vendor Red Hat Product Security CVE-2026-21226 · 16 productsAffected
  5. No fix planned, says the vendor Red Hat Product Security CVE-2026-21226 · 4 productsOut of support scope

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

  • NVDCVE recordread 2026-10-23
  • CISA-ADPSSVC decisionnone2026-01-13
  • CNACVSS 3.17.5known since 2026-10-23
  • CNAweakness (CWE)CWE-502known since 2026-10-23
  • FIRST EPSSEPSS score1.0 %2026-11-08
  • OSVaffected packages—
  • GitHub AdvisoriesadvisoryHIGH2026-01-13

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Published
2026-01-13
Last Modified
2026-06-17
NVD status
Analyzed
GitHub Advisory
GHSA-jm66-cg57-jjv5

Frequently asked questions

What is CVE-2026-21226?

Deserialization of untrusted data in Azure Core shared client library for Python allows an authorized attacker to execute code over a network.

Is CVE-2026-21226 actively exploited?

Active exploitation of CVE-2026-21226 has not been confirmed. Its EPSS score was 1.0% on 2026-11-08, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-21226?

CVE-2026-21226 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.

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