CVE-2026-56309

MEDIUMPre-NVD 5.45.4
EchelonGraph scoreHIGH confidence

Score 5.4 from GitHub Security Advisory published 2026-07-10. a secondary CVSS source baseline 5.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Elevated
5.4
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.4Exploit: 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 fails to enforce plan/quota restrictions on the /files/upload/attachments endpoint, allowing plan-blocked apps to create publicly readable R2 objects. Attackers can upload arbitrary attachments using upload-scoped API keys that bypass plan checks, persist outside normal bundle metadata, and survive app deletion, enabling storage and bandwidth abuse.

CVSS v3
5.4
EG Score
5.4(high)
EG Risk
40(Track)
EG Risk 40/100SSVC: 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
Severity54% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
17.5%
KEV
Not listed

Published

July 10, 2026

Last Modified

July 10, 2026

Advisory Details (2)

Auto-updated Jul 10, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Plan-blocked apps can still create publicly readable orphaned R2 attachments that survive app deletion · Advisory · Cap-go/capgo · GitHub

https://github.com/Cap-go/capgo/security/advisories/GHSA-q52j-ggvx-cr4v
generic

Capgo - Plan Bypass via Unrestricted Attachment Upload Endpoint | Advisories | VulnCheck

https://www.vulncheck.com/advisories/capgo-plan-bypass-via-unrestricted-attachment-upload-endpoint

Vendor Advisories for CVE-2026-56309(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 10× in last 7d / 27× 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. 2026-07-24 14:18 UTCEPSS rescore
  2. 2026-07-23 14:18 UTCEPSS rescore
  3. 2026-07-23 03:20 UTCEG score recompute
  4. 2026-07-22 14:08 UTCEPSS rescore
  5. 2026-07-21 15:25 UTCEPSS rescore
  6. 2026-07-20 17:08 UTCEPSS rescore
  7. 2026-07-19 14:31 UTCEPSS rescore
  8. 2026-07-19 14:31 UTCEPSS rescore
  9. 2026-07-19 02:29 UTCEPSS rescore
  10. 2026-07-18 10:04 UTCEPSS rescore
  11. 2026-07-16 17:03 UTCEPSS rescore
  12. 2026-07-16 09:12 UTCGHSA enrichment
  13. 2026-07-15 16:57 UTCEPSS rescore
  14. 2026-07-15 16:57 UTCEPSS rescore
  15. 2026-07-15 10:07 UTCGHSA enrichment
  16. 2026-07-15 02:00 UTCEPSS rescore
  17. 2026-07-15 02:00 UTCEPSS rescore
  18. 2026-07-14 11:02 UTCGHSA enrichment
  19. 2026-07-13 22:31 UTCEPSS rescore
  20. 2026-07-13 11:57 UTCGHSA enrichment
  21. 2026-07-13 06:13 UTCEPSS rescore
  22. 2026-07-13 06:13 UTCEPSS rescore
  23. 2026-07-12 12:53 UTCGHSA enrichment
  24. 2026-07-12 05:46 UTCEPSS rescore
  25. 2026-07-11 13:48 UTCGHSA enrichment
Show 2 more
  1. 2026-07-10 14:43 UTCEG score recompute
  2. 2026-07-10 14:42 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-56309?
CVE-2026-56309 is a medium vulnerability published on July 10, 2026. Capgo before 12.128.2 fails to enforce plan/quota restrictions on the /files/upload/attachments endpoint, allowing plan-blocked apps to create publicly readable R2 objects. Attackers can upload arbitrary attachments using upload-scoped API keys that bypass plan checks, persist outside normal bundle…
When was CVE-2026-56309 disclosed?
CVE-2026-56309 was first published in the National Vulnerability Database on July 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56309 actively exploited?
CVE-2026-56309 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 17.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-56309?
CVE-2026-56309 has a CVSS v3 base score of 5.4 (NVD).
How do I remediate CVE-2026-56309?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56309, 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

Explore the affected products and dependency analysis for CVE-2026-56309

Explore →

Is Your Infrastructure Affected by CVE-2026-56309?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.