Run-state corruption via unvalidated protobuf events
Published Nov 1, 2026 · Updated Nov 1, 2026
Schema bypass in AG-UI 0.0.58 and earlier allows remote attackers to disrupt client runs via malformed protobuf events. The client's transformHttpEventStream emits protobuf-decoded events without EventSchemas.parse, allowing invalid field types into the run reducer. Exploitation requires control of the event producer or interception of its responses; the demonstrated numeric message identifier leaves an active message that prevents normal run completion.
Summary
What happened
Schema bypass in AG-UI 0.0.58 and earlier allows remote attackers to disrupt client runs via malformed protobuf events. The client's transformHttpEventStream emits protobuf-decoded events without EventSchemas.parse, allowing invalid field types into the run reducer. Exploitation requires control of the event producer or interception of its responses; the demonstrated numeric message identifier leaves an active message that prevents normal run completion.
The record
- CVE
- CVE-2026-120236
- Published
- Nov 1, 2026
- Updated
- Nov 1, 2026
- Vendor
- AG-UI Protocol
- Product
- AG-UI
- Classifications
- CWE-20
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Nov 1, 2026CVE publishedPublication date reported by the CVE source.
- Nov 1, 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.
- Affected versionversion=0.0.1
- Affected versionversion=0.0.10
- Affected versionversion=0.0.11
- Affected versionversion=0.0.12
- Affected versionversion=0.0.13
- Affected versionversion=0.0.14
- Affected versionversion=0.0.15
- Affected versionversion=0.0.16
- Affected versionversion=0.0.17
- Affected versionversion=0.0.18
- Affected versionversion=0.0.19
- Affected versionversion=0.0.2
- Affected versionversion=0.0.20
- Affected versionversion=0.0.21
- Affected versionversion=0.0.22
- Affected versionversion=0.0.23
- Affected versionversion=0.0.24
- Affected versionversion=0.0.25
- Affected versionversion=0.0.26
- Affected versionversion=0.0.27
- Affected versionversion=0.0.28
- Affected versionversion=0.0.29
- Affected versionversion=0.0.3
- Affected versionversion=0.0.30
- Affected versionversion=0.0.31
- Affected versionversion=0.0.32
- Affected versionversion=0.0.33
- Affected versionversion=0.0.34
- Affected versionversion=0.0.35
- Affected versionversion=0.0.36
- Affected versionversion=0.0.37
- Affected versionversion=0.0.38
- Affected versionversion=0.0.39
- Affected versionversion=0.0.4
- Affected versionversion=0.0.40
- Affected versionversion=0.0.41
- Affected versionversion=0.0.42
- Affected versionversion=0.0.43
- Affected versionversion=0.0.44
- Affected versionversion=0.0.45
- Affected versionversion=0.0.46
- Affected versionversion=0.0.47
- Affected versionversion=0.0.48
- Affected versionversion=0.0.49
- Affected versionversion=0.0.5
- Affected versionversion=0.0.50
- Affected versionversion=0.0.51
- Affected versionversion=0.0.52
- Affected versionversion=0.0.53
- Affected versionversion=0.0.54
- Affected versionversion=0.0.55
- Affected versionversion=0.0.56
- Affected versionversion=0.0.57
- Affected versionversion=0.0.58
- Affected versionversion=0.0.6
- Affected versionversion=0.0.7
- Affected versionversion=0.0.8
- Affected versionversion=0.0.9
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
- Protobuf event-validation bypass proof of conceptproof of concept · demonstrated
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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