CVE-2026-56312: Auth Bypass (CVSS 6.5)

Description

Capgo before 12.128.2 contains an improper validation vulnerability in the accept_invitation endpoint that creates user accounts before captcha validation is enforced. Attackers can bypass captcha protection by sending POST requests with invalid captcha tokens to create unwanted accounts and burn invite links.

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CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

EPSS — Exploit Prediction

0.0028

Probability of exploitation

0.20%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-287 Improper Authentication

References

Other References

https://github.com/Cap-go/capgo/security/advisories/GHSA-whc5-fvr7-g5v3 https://www.vulncheck.com/advisories/capgo-account-creation-before-captcha-validation-in-accept-invitation-endpoint

Frequently Asked Questions

What is CVE-2026-56312? +

Capgo before 12.128.2 contains an improper validation vulnerability in the accept_invitation endpoint that creates user accounts before captcha validation is enforced. Attackers can bypass captcha protection by sending POST requests with invalid captcha tokens to create unwanted accounts and burn invite links. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-56312? +

CVE-2026-56312 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0028, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-56312? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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