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
Trending — 4 sources updated this weekElevated
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)
EPSS
17.3%
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 11× in last 7d / 11× 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. 2026-07-13 11:57 UTCEG score recompute
  2. 2026-07-13 11:57 UTCGHSA enrichment
  3. 2026-07-13 06:13 UTCEPSS rescore
  4. 2026-07-13 06:13 UTCEPSS rescore
  5. 2026-07-12 12:53 UTCEG score recompute
  6. 2026-07-12 12:53 UTCGHSA enrichment
  7. 2026-07-12 05:46 UTCEPSS rescore
  8. 2026-07-11 13:48 UTCEG score recompute
  9. 2026-07-11 13:48 UTCGHSA enrichment
  10. 2026-07-10 14:43 UTCEG score recompute
  11. 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 17.3% 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

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