CVE-2026-56306

MEDIUM EPSS 16.3%
Published Jun 22, 20261w ago · Modified Jun 23, 20261w ago
5.3 CVSS 4.0
Medium
Find Similar
Published Jun 22, 2026 1w ago
Last Modified Jun 23, 2026 1w ago

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.

CVSS Details

Base Score
5.3
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
16.3% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-20 Improper Input Validation Validation

References 2

  • github.com https://github.com/Cap-go/capgo/security/advisories/GHSA-42vv-8j94-24wj
  • vulncheck.com https://www.vulncheck.com/advisories/capgo-subkey-enforcement-bypass-via-x-limited-key-id-header-parsing

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.