How severe is CVE-2026-56299?

CVE-2026-56299 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2026-56299 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-56299?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-56299 have an EU (EUVD) identifier?

Yes. CVE-2026-56299 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38171.

When was CVE-2026-56299 published?

CVE-2026-56299 was published on 2026-06-21 and last updated on 2026-06-23.

CVE-2026-56299

CVE-2026-56299 is a medium-severity vulnerability with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-306.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v4: 6.9
EPSS exploit prediction: 0% (31st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-38171
Weakness: CWE-306
Published: 2026-06-21
Last modified: 2026-06-23

Description

Capgo before 12.128.2 contains an authentication bypass vulnerability in the /build/upload/:jobId/* endpoint that allows unauthenticated attackers to trigger consistent 500 errors. Remote attackers can send OPTIONS requests to bypass authentication middleware and invoke tusProxy logic with invalid credentials, enabling trivial request flooding and denial of service.

Frequently asked questions

What is CVE-2026-56299?: Capgo before 12.128.2 contains an authentication bypass vulnerability in the /build/upload/:jobId/* endpoint that allows unauthenticated attackers to trigger consistent 500 errors. Remote attackers can send OPTIONS requests to bypass authentication middleware and invoke tusProxy logic with invalid credentials, enabling trivial request flooding and denial of service.
How severe is CVE-2026-56299?: CVE-2026-56299 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2026-56299 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-56299?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-56299 have an EU (EUVD) identifier?: Yes. CVE-2026-56299 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38171.
When was CVE-2026-56299 published?: CVE-2026-56299 was published on 2026-06-21 and last updated on 2026-06-23.

References

Other CWE-306 (Missing Authentication for Critical Function) vulnerabilities

CVE-2026-54309 — Critical (CVSS 10.0): n8n is an open source workflow automation platform. Prior to 2.25.7 and 2.26.2, when @n8n/mcp-browser is run in HTTP…
CVE-2026-50242 — Critical (CVSS 10.0): In JetBrains Hub before 2026.1.13757, 2025.3.148033, 2025.2.148048, 2025.1.148120, 2024.3.148430, 2024.2.148429…
CVE-2026-49257 — Critical (CVSS 10.0): mcp-pinot is a Python-based Model Context Protocol (MCP) server for interacting with Apache Pinot. In versions 3.0.1…
CVE-2026-46846 — Critical (CVSS 10.0): Vulnerability in the Oracle WebCenter Portal product of Oracle Fusion Middleware (component: Security Framework).…
CVE-2026-46803 — Critical (CVSS 10.0): Vulnerability in the Oracle WebCenter Portal product of Oracle Fusion Middleware (component: Security Framework).…
CVE-2026-46800 — Critical (CVSS 10.0): Vulnerability in the Oracle WebCenter Sites product of Oracle Fusion Middleware (component: WebCenter Sites).…

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