Authenticated storage abuse via unchecked attachment uploads
Published Jul 10, 2026 · Updated Jul 10, 2026
Improper authorization in Capgo before 12.128.2 allows remote authenticated users to create public R2 objects through attachment uploads. The /files/upload/attachments route checks app.read_bundles but omits the plan and quota gate used by /updates, then writes supplied bytes to R2 outside bundle metadata. An upload-scoped API key for a plan-blocked app is required; resulting objects remain publicly readable and survive normal app deletion, enabling storage and bandwidth abuse.
Summary
What happened
Improper authorization in Capgo before 12.128.2 allows remote authenticated users to create public R2 objects through attachment uploads. The /files/upload/attachments route checks app.read_bundles but omits the plan and quota gate used by /updates, then writes supplied bytes to R2 outside bundle metadata. An upload-scoped API key for a plan-blocked app is required; resulting objects remain publicly readable and survive normal app deletion, enabling storage and bandwidth abuse.
The record
- CVE
- CVE-2026-56309
- Published
- Jul 10, 2026
- Updated
- Jul 10, 2026
- Vendor
- Capgo
- Product
- Capgo
- Classifications
- CWE-770, T1496.002
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 10, 2026CVE publishedPublication date reported by the CVE source.
- Jul 10, 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 <12.128.2
What conditions does exploitation require?
What is affected?
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.
Weakness, pattern, technique
Public exploit references
- Vendor advisory attachment-upload proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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