CVE-2026-56299

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreHIGH confidence

Score 5.3 from GitHub Security Advisory published 2026-06-21. a secondary CVSS source baseline 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
5.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.3Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
5.3
EG Score
5.3(high)
EPSS
31.0%
KEV
Not listed

Published

June 21, 2026

Last Modified

June 23, 2026

Advisory Details (2)

Auto-updated Jun 23, 2026
🔬 Proof of concept available. Patch available. Sources: github.
generic

Capgo - Denial of Service via Unauthenticated OPTIONS Request to /build/upload Endpoint | Advisories | VulnCheck

https://www.vulncheck.com/advisories/capgo-denial-of-service-via-unauthenticated-options-request-to-build-upload-endpoint
github Patch Available🟡 PoC Available

Unauthenticated OPTIONS to /build/upload/:jobId/* triggers consistent 500 (reliable external error/DoS vector) · Advisory · Cap-go/capgo · GitHub

https://github.com/Cap-go/capgo/security/advisories/GHSA-6c7m-4223-446j

Vendor Advisories for CVE-2026-56299(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 24× in last 7d / 53× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-06 21:33 UTCEG score recompute
  2. 2026-07-06 21:32 UTCGHSA enrichment
  3. 2026-07-06 16:27 UTCEPSS rescore
  4. 2026-07-06 16:27 UTCEPSS rescore
  5. 2026-07-06 02:23 UTCEPSS rescore
  6. 2026-07-06 02:23 UTCEPSS rescore
  7. 2026-07-05 21:10 UTCEG score recompute
  8. 2026-07-05 21:10 UTCGHSA enrichment
  9. 2026-07-05 02:31 UTCEPSS rescore
  10. 2026-07-05 02:30 UTCEPSS rescore
  11. 2026-07-04 20:46 UTCEG score recompute
  12. 2026-07-04 20:45 UTCGHSA enrichment
  13. 2026-07-04 06:31 UTCEPSS rescore
  14. 2026-07-04 06:31 UTCEPSS rescore
  15. 2026-07-03 20:22 UTCEG score recompute
  16. 2026-07-03 20:22 UTCGHSA enrichment
  17. 2026-07-02 19:59 UTCEG score recompute
  18. 2026-07-02 19:59 UTCGHSA enrichment
  19. 2026-07-01 19:37 UTCEG score recompute
  20. 2026-07-01 19:37 UTCGHSA enrichment
  21. 2026-07-01 15:07 UTCEPSS rescore
  22. 2026-06-30 23:22 UTCEPSS rescore
  23. 2026-06-30 19:15 UTCEG score recompute
  24. 2026-06-30 19:15 UTCGHSA enrichment
  25. 2026-06-29 18:52 UTCEG score recompute
Show 28 more
  1. 2026-06-29 18:52 UTCGHSA enrichment
  2. 2026-06-29 14:06 UTCEPSS rescore
  3. 2026-06-29 14:06 UTCEPSS rescore
  4. 2026-06-28 18:29 UTCEG score recompute
  5. 2026-06-28 18:29 UTCGHSA enrichment
  6. 2026-06-28 14:07 UTCEPSS rescore
  7. 2026-06-28 04:56 UTCEPSS rescore
  8. 2026-06-28 04:56 UTCEPSS rescore
  9. 2026-06-27 18:06 UTCEG score recompute
  10. 2026-06-27 18:06 UTCGHSA enrichment
  11. 2026-06-27 03:08 UTCEPSS rescore
  12. 2026-06-26 17:44 UTCEG score recompute
  13. 2026-06-26 17:44 UTCGHSA enrichment
  14. 2026-06-25 17:21 UTCEG score recompute
  15. 2026-06-25 17:21 UTCGHSA enrichment
  16. 2026-06-25 13:49 UTCEPSS rescore
  17. 2026-06-24 16:59 UTCEG score recompute
  18. 2026-06-24 16:59 UTCGHSA enrichment
  19. 2026-06-24 14:05 UTCEPSS rescore
  20. 2026-06-23 21:33 UTCEPSS rescore
  21. 2026-06-23 21:33 UTCEPSS rescore
  22. 2026-06-23 16:37 UTCEG score recompute
  23. 2026-06-23 16:36 UTCGHSA enrichment
  24. 2026-06-22 19:39 UTCNVD updateCVSS v4 → 6.9
  25. 2026-06-22 16:13 UTCEG score recompute
  26. 2026-06-22 16:13 UTCGHSA enrichment
  27. 2026-06-21 15:38 UTCEG score recompute
  28. 2026-06-21 15:38 UTCGHSA enrichment

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-56299?
CVE-2026-56299 is a medium vulnerability published on June 21, 2026. 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…
When was CVE-2026-56299 disclosed?
CVE-2026-56299 was first published in the National Vulnerability Database on June 21, 2026, with the most recent update on June 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56299 actively exploited?
CVE-2026-56299 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 31.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-56299?
CVE-2026-56299 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-56299?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56299, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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