CVE-2026-56306 Capgo - Subkey Enforcement Bypass via x-limited-key-id Header Parsing
Attackers can bypass subkey restrictions by manipulating the x-limited-key-id header, allowing execution of requests with main API key privileges.
- 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-2026-56306?
CVE-2026-56306 is a medium-severity authentication bypass vulnerability in Capgo, published on 22 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Capgo before 12.128.2 contains a weak parsing vulnerability in the x-limited-key-id header that allows attackers to bypass subkey enforcement by submitting malformed values, zero, or duplicate headers that result in NaN or falsy values. Remote attackers can manipulate the x-limited-key-id header to disable limited key scoping and execute requests using the main API key context instead of restricted subkey permissions.
Weakness: CWE-20
Which versions are affected by CVE-2026-56306?
How do I fix CVE-2026-56306?
No fix has been published for CVE-2026-56306 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-56306 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-56306 exists.
Sources
Also known as GHSA-42vv-8j94-24wj.