What is CVE-2026-56331?

CVE-2026-56331 is a medium-severity vulnerability in Capgo, classified under Generation of Error Message Containing Sensitive Information. CVSS score: 5.3/10. Published 2026-06-30.

How severe is CVE-2026-56331?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Information disclosure in Capgo

CVE-2026-56331

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.

Published 2026-06-30 · last modified 2026-07-01.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.003 (25.4th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 25th percentile — 25.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Capgo — versions 0, 12.128.2

Weakness classification (CWE)

CWE-209 — Generation of Error Message Containing Sensitive Information

References

github.com/Cap-go/capgo/security/advisories/GHSA-34p8-fh3m-376x (vendor-advisory)
www.vulncheck.com/advisories/capgo-improper-error-handling-in-accept-invitation… (third-party-advisory)

Frequently asked questions

What is CVE-2026-56331?: CVE-2026-56331 is a medium-severity vulnerability in Capgo, classified under Generation of Error Message Containing Sensitive Information. CVSS score: 5.3/10. Published 2026-06-30.
How severe is CVE-2026-56331?: Medium severity. CVSS v3 base score is 5.3 out of 10.