CVE-2026-56306

Medium

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.

SeverityMedium

CVSS6.4

Exploit probability—

ProductCapgo

PublishedJun 22, 2026

First seenJun 22, 2026

Weakness typeCWE-20Improper input validation

How to fix

Update

Capgo Capgo12.128.2 or later

Vendor advisories

github.com/Cap-go/capgo/security/advisories/GHSA-42vv-8j94-24wj

Affected products

Product	Affected versions	Fixed in
Capgo Capgo	v < 12.128.2	12.128.2

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