CVE-2026-56331

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreHIGH confidence

Score 5.3 from GitHub Security Advisory published 2026-07-01. a secondary CVSS source baseline 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
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 improper error handling in the /private/accept_invitation endpoint that returns HTTP 500 instead of safe 4xx errors when magic_invite_string is invalid. Attackers can trigger this vulnerability using only the public key by submitting malformed magic_invite_string values to cause server errors and leak internal processing details.

CVSS v3
5.3
EG Score
5.3(high)
EG Risk
28(Track)
EG Risk 28/100SSVC: 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%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
16.4%
KEV
Not listed

Published

July 1, 2026

Last Modified

July 1, 2026

Advisory Details (2)

Auto-updated Jul 3, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

500 Internal Server Error on /private/accept_invitation when magic_invite_string is invalid (tmp_users “single JSON object” coercion) · Advisory · Cap-go/capgo · GitHub

https://github.com/Cap-go/capgo/security/advisories/GHSA-34p8-fh3m-376x
generic

Capgo - Improper Error Handling in Accept Invitation Endpoint via Invalid Magic String | Advisories | VulnCheck

https://www.vulncheck.com/advisories/capgo-improper-error-handling-in-accept-invitation-endpoint-via-invalid-magic-string

Vendor Advisories for CVE-2026-56331(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 / 54× 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 08:41 UTCGHSA enrichment
  16. 2026-07-15 02:00 UTCEPSS rescore
  17. 2026-07-15 02:00 UTCEPSS rescore
  18. 2026-07-14 08:08 UTCGHSA enrichment
  19. 2026-07-13 22:31 UTCEPSS rescore
  20. 2026-07-13 07:37 UTCGHSA enrichment
  21. 2026-07-13 06:13 UTCEPSS rescore
  22. 2026-07-13 06:13 UTCEPSS rescore
  23. 2026-07-12 07:06 UTCGHSA enrichment
  24. 2026-07-12 05:46 UTCEPSS rescore
  25. 2026-07-11 08:27 UTCEPSS rescore
Show 29 more
  1. 2026-07-11 08:27 UTCEPSS rescore
  2. 2026-07-11 06:34 UTCGHSA enrichment
  3. 2026-07-10 06:03 UTCGHSA enrichment
  4. 2026-07-09 19:10 UTCEPSS rescore
  5. 2026-07-09 19:10 UTCEPSS rescore
  6. 2026-07-09 05:32 UTCGHSA enrichment
  7. 2026-07-08 15:16 UTCEPSS rescore
  8. 2026-07-08 15:16 UTCEPSS rescore
  9. 2026-07-08 04:59 UTCGHSA enrichment
  10. 2026-07-07 13:46 UTCEPSS rescore
  11. 2026-07-07 13:46 UTCEPSS rescore
  12. 2026-07-07 04:29 UTCGHSA enrichment
  13. 2026-07-06 16:27 UTCEPSS rescore
  14. 2026-07-06 16:27 UTCEPSS rescore
  15. 2026-07-06 03:57 UTCGHSA enrichment
  16. 2026-07-06 02:23 UTCEPSS rescore
  17. 2026-07-06 02:23 UTCEPSS rescore
  18. 2026-07-05 03:26 UTCGHSA enrichment
  19. 2026-07-05 02:31 UTCEPSS rescore
  20. 2026-07-05 02:30 UTCEPSS rescore
  21. 2026-07-04 06:31 UTCEPSS rescore
  22. 2026-07-04 06:31 UTCEPSS rescore
  23. 2026-07-04 02:55 UTCGHSA enrichment
  24. 2026-07-03 02:21 UTCGHSA enrichment
  25. 2026-07-02 01:50 UTCGHSA enrichment
  26. 2026-07-01 17:06 UTCNVD updateCVSS v4 → 6.9
  27. 2026-07-01 15:07 UTCEPSS rescore
  28. 2026-07-01 01:20 UTCEG score recompute
  29. 2026-07-01 01:20 UTCGHSA enrichment

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-56331?
CVE-2026-56331 is a medium vulnerability published on July 1, 2026. Capgo before 12.128.2 contains improper error handling in the /private/acceptinvitation endpoint that returns HTTP 500 instead of safe 4xx errors when magicinvitestring is invalid. Attackers can trigger this vulnerability using only the public key by submitting malformed magicinvite_string values…
When was CVE-2026-56331 disclosed?
CVE-2026-56331 was first published in the National Vulnerability Database on July 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56331 actively exploited?
CVE-2026-56331 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 16.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-56331?
CVE-2026-56331 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-56331?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56331, 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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