CVE-2026-56306
MEDIUMCapgo - Subkey Enforcement Bypass via x-limited-key-id Header Parsing
Title source: cnaDescription
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.
References (2)
Core 2
Core References
Vendor Advisory vendor-advisory
GitHub Security Advisory (GHSA-42vv-8j94-24wj)
https://github.com/Cap-go/capgo/security/advisories/GHSA-42vv-8j94-24wj
Third Party Advisory third-party-advisory
VulnCheck Advisory: Capgo - Subkey Enforcement Bypass via x-limited-key-id Header Parsing
https://www.vulncheck.com/advisories/capgo-subkey-enforcement-bypass-via-x-limited-key-id-header-parsing
Scores
CVSS v3
6.4
EPSS
0.0025
EPSS Percentile
16.3%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
no
Technical Impact
partial
Details
CWE
CWE-20
Status
published
Products (2)
Capgo/Capgo
< 12.128.2
Capgo/Capgo
12.128.2
Published
Jun 22, 2026
Tracked Since
Jun 23, 2026