CVE-2026-72923Public exploitNetwork attack vector

Process termination via exponential YAML alias materialization

Published Sep 8, 2026 · Updated Sep 8, 2026

Uncontrolled resource consumption in affected Microsoft OpenAPI YAML readers allows remote attackers to terminate processes via crafted YAML. YamlConverter materializes every SharpYaml alias as a separate JsonNode, causing nested anchors and aliases to expand exponentially without node or depth bounds. Exposure requires an application, CLI, developer tool, or service to parse attacker-influenced YAML in process; the documented consequence is memory exhaustion and process termination only.

CVSS severity7.5
High
EPSS probability1.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled resource consumption in affected Microsoft OpenAPI YAML readers allows remote attackers to terminate processes via crafted YAML. YamlConverter materializes every SharpYaml alias as a separate JsonNode, causing nested anchors and aliases to expand exponentially without node or depth bounds. Exposure requires an application, CLI, developer tool, or service to parse attacker-influenced YAML in process; the documented consequence is memory exhaustion and process termination only.

The record

CVE
CVE-2026-72923
Published
Sep 8, 2026
Updated
Sep 8, 2026
Vendor
Microsoft
Product
Microsoft.OpenApi.Readers
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <1.6.30 changes=[{"at":"1.6.30","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft.OpenApi.Readersversion=0 <1.6.30 changes=[{"at":"1.6.30","status":"unaffected"}]
Microsoft · Microsoft.OpenApi.YamlReaderversion=2.0.0-preview.11 <2.12.0 changes=[{"at":"2.12.0","status":"unaffected"}]; version=3.0.0 <3.10.0 changes=[{"at":"3.10.0","status":"unaffected"}]

Published CVSS scores

7.5GitHub CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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