CVE-2026-56309 Capgo - Plan Bypass via Unrestricted Attachment Upload Endpoint
Attackers can bypass plan restrictions to upload arbitrary files, causing storage and bandwidth abuse in Capgo update services.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-56309?
CVE-2026-56309 is a medium-severity missing authorization vulnerability in Capgo, published on 10 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Capgo before 12.128.2 fails to enforce plan/quota restrictions on the /files/upload/attachments endpoint, allowing plan-blocked apps to create publicly readable R2 objects. Attackers can upload arbitrary attachments using upload-scoped API keys that bypass plan checks, persist outside normal bundle metadata, and survive app deletion, enabling storage and bandwidth abuse.
Weakness: CWE-770
Which versions are affected by CVE-2026-56309?
How do I fix CVE-2026-56309?
No fix has been published for CVE-2026-56309 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-56309 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-56309 exists.
Sources
Also known as GHSA-644w-64m3-9c8v, GHSA-q52j-ggvx-cr4v.