CVE-2026-56299

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM 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
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 5.3Exploit: None knownExposed: 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(medium)
EG Risk
39(Track)
EG Risk 39/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity53% × 45%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
50%
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 5× in last 7d / 48× 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.

Showing the most recent 100 of 167 total refreshes for this CVE.

  1. 2026-09-11 14:53 UTCEPSS rescore
  2. 2026-09-10 09:35 UTCEPSS rescore
  3. 2026-09-08 22:01 UTCEPSS rescore
  4. 2026-09-07 16:01 UTCEPSS rescore
  5. 2026-09-06 13:47 UTCEPSS rescore
  6. 2026-09-04 05:07 UTCEPSS rescore
  7. 2026-09-02 14:12 UTCEPSS rescore
  8. 2026-09-01 13:54 UTCEPSS rescore
  9. 2026-09-01 04:40 UTCEPSS rescore
  10. 2026-08-30 20:42 UTCEG score recompute
  11. 2026-08-30 20:42 UTCGHSA enrichment
  12. 2026-08-30 19:17 UTCEPSS rescore
  13. 2026-08-30 01:22 UTCEPSS rescore
  14. 2026-08-28 21:41 UTCEPSS rescore
  15. 2026-08-27 14:25 UTCEPSS rescore
  16. 2026-08-26 14:46 UTCEPSS rescore
  17. 2026-08-25 13:49 UTCEPSS rescore
  18. 2026-08-24 23:40 UTCEG score recompute
  19. 2026-08-24 23:40 UTCGHSA enrichment
  20. 2026-08-23 23:18 UTCEG score recompute
  21. 2026-08-23 23:18 UTCGHSA enrichment
  22. 2026-08-23 00:19 UTCEPSS rescore
  23. 2026-08-22 22:56 UTCEG score recompute
  24. 2026-08-22 22:56 UTCGHSA enrichment
  25. 2026-08-21 23:49 UTCEPSS rescore
Show 75 more
  1. 2026-08-21 08:16 UTCEG score recompute
  2. 2026-08-21 08:16 UTCGHSA enrichment
  3. 2026-08-20 22:55 UTCEPSS rescore
  4. 2026-08-20 07:53 UTCEG score recompute
  5. 2026-08-20 07:53 UTCGHSA enrichment
  6. 2026-08-19 17:04 UTCEPSS rescore
  7. 2026-08-19 05:47 UTCEG score recompute
  8. 2026-08-19 05:47 UTCGHSA enrichment
  9. 2026-08-18 13:48 UTCEPSS rescore
  10. 2026-08-17 13:47 UTCEPSS rescore
  11. 2026-08-16 21:53 UTCEG score recompute
  12. 2026-08-16 21:53 UTCGHSA enrichment
  13. 2026-08-16 14:56 UTCEPSS rescore
  14. 2026-08-16 02:14 UTCEPSS rescore
  15. 2026-08-15 21:31 UTCEG score recompute
  16. 2026-08-15 21:31 UTCGHSA enrichment
  17. 2026-08-15 01:30 UTCEPSS rescore
  18. 2026-08-14 21:08 UTCEG score recompute
  19. 2026-08-14 21:08 UTCGHSA enrichment
  20. 2026-08-13 22:00 UTCEPSS rescore
  21. 2026-08-13 20:46 UTCGHSA enrichment
  22. 2026-08-12 20:16 UTCEG score recompute
  23. 2026-08-12 20:16 UTCGHSA enrichment
  24. 2026-08-12 13:51 UTCEPSS rescore
  25. 2026-08-11 19:54 UTCEG score recompute
  26. 2026-08-11 19:54 UTCGHSA enrichment
  27. 2026-08-11 00:00 UTCEPSS rescore
  28. 2026-08-10 19:32 UTCGHSA enrichment
  29. 2026-08-09 19:10 UTCEG score recompute
  30. 2026-08-09 19:10 UTCGHSA enrichment
  31. 2026-08-09 13:46 UTCEPSS rescore
  32. 2026-08-08 18:48 UTCEG score recompute
  33. 2026-08-08 18:48 UTCGHSA enrichment
  34. 2026-08-08 16:37 UTCEPSS rescore
  35. 2026-08-07 18:25 UTCEG score recompute
  36. 2026-08-07 18:25 UTCGHSA enrichment
  37. 2026-08-06 18:03 UTCEG score recompute
  38. 2026-08-06 18:03 UTCGHSA enrichment
  39. 2026-08-06 13:47 UTCEPSS rescore
  40. 2026-08-05 19:17 UTCEPSS rescore
  41. 2026-08-05 17:40 UTCGHSA enrichment
  42. 2026-08-04 15:17 UTCEG score recompute
  43. 2026-08-04 15:17 UTCGHSA enrichment
  44. 2026-08-04 15:10 UTCEPSS rescore
  45. 2026-08-04 10:39 UTCEPSS rescore
  46. 2026-08-03 10:36 UTCEPSS rescore
  47. 2026-08-03 08:00 UTCGHSA enrichment
  48. 2026-08-02 05:20 UTCEG score recompute
  49. 2026-08-02 05:20 UTCGHSA enrichment
  50. 2026-08-02 02:27 UTCEPSS rescore
  51. 2026-08-01 04:57 UTCEG score recompute
  52. 2026-08-01 04:57 UTCGHSA enrichment
  53. 2026-08-01 04:16 UTCEPSS rescore
  54. 2026-07-31 03:46 UTCEG score recompute
  55. 2026-07-31 03:45 UTCGHSA enrichment
  56. 2026-07-30 16:28 UTCEPSS rescore
  57. 2026-07-30 02:49 UTCEG score recompute
  58. 2026-07-30 02:49 UTCGHSA enrichment
  59. 2026-07-30 01:30 UTCEPSS rescore
  60. 2026-07-30 01:30 UTCEPSS rescore
  61. 2026-07-29 01:27 UTCEG score recompute
  62. 2026-07-29 01:27 UTCGHSA enrichment
  63. 2026-07-28 15:37 UTCEPSS rescore
  64. 2026-07-27 18:00 UTCEG score recompute
  65. 2026-07-27 18:00 UTCGHSA enrichment
  66. 2026-07-26 16:18 UTCEG score recompute
  67. 2026-07-26 16:18 UTCGHSA enrichment
  68. 2026-07-26 14:54 UTCEPSS rescore
  69. 2026-07-25 14:18 UTCEPSS rescore
  70. 2026-07-24 14:18 UTCEPSS rescore
  71. 2026-07-23 14:18 UTCEPSS rescore
  72. 2026-07-23 03:20 UTCEG score recompute
  73. 2026-07-22 14:08 UTCEPSS rescore
  74. 2026-07-21 15:25 UTCEPSS rescore
  75. 2026-07-20 17:08 UTCEPSS rescore

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 1% probability of exploitation in the next 30 days, which ranks it in the top 49.5% of all scored CVEs.
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.

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