CVE-2026-61534Public exploitNetwork attack vector

Process-wide logic corruption via prototype pollution

Published Sep 14, 2026 · Updated Sep 14, 2026

Prototype pollution in Confetti Yayson 4.2.0 and earlier allows remote attackers to corrupt process-wide object behavior via JSON:API data. Store and LegacyStore index plain-object caches directly with document-controlled type, id, and relationship names, so a proto type redirects model writes into Object.prototype. Exploitation requires a consuming application to pass attacker-controlled JSON:API documents; denial of service and logic corruption are direct, while authorization bypass or code execution requires a suitable application gadget.

CVSS severity9.1
Critical
EPSS probability0.78%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Prototype pollution in Confetti Yayson 4.2.0 and earlier allows remote attackers to corrupt process-wide object behavior via JSON:API data. Store and LegacyStore index plain-object caches directly with document-controlled type, id, and relationship names, so a proto type redirects model writes into Object.prototype. Exploitation requires a consuming application to pass attacker-controlled JSON:API documents; denial of service and logic corruption are direct, while authorization bypass or code execution requires a suitable application gadget.

The record

CVE
CVE-2026-61534
Published
Sep 14, 2026
Updated
Sep 14, 2026
Vendor
Confetti
Product
Yayson
Classifications
CWE-1321, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 14, 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=< 4.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Confetti · Yaysonversion=< 4.3.0

Published CVSS scores

8.1ConfettiCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
9.1GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/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-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
T1190Exploit Public-Facing Application

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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