CVE-2026-100306 (CVSS 5.3)

Description

TDuck survey form through 6.0 fails to validate write passwords on submission endpoints, enforcing the check only on the front end. Remote unauthenticated attackers can submit form entries directly to public submission APIs without providing the password by using the form key from share links.

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CVSS v3.1 Score

5.3

MEDIUM

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

EPSS — Exploit Prediction

0.0039

Probability of exploitation

0.32%

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-602 CWE-602

References

Other References

https://github.com/LinYuanyi1/cve-request-poc/blob/adffc39b78cad18cd489cbf7454853bf0f744b7f/tduck/poc_form_data_create_bypass.py https://github.com/TDuckCloud/tduck-survey-form https://github.com/TDuckCloud/tduck-survey-form/blob/43ffa9c993e38936fc4de7d8e5aee82bbaa19502/tduck-api/src/main/java/com/tduck/cloud/api/web/controller/UserFormResultController.java#L152-L172 https://github.com/TDuckCloud/tduck-survey-form/blob/43ffa9c993e38936fc4de7d8e5aee82bbaa19502/tduck-api/src/main/java/com/tduck/cloud/api/web/controller/UserFormSettingController.java#L154-L162 https://www.vulncheck.com/advisories/tduck-survey-form-through-6.0-write-password-bypass-via-client-side-enforcement

Frequently Asked Questions

What is CVE-2026-100306? +

TDuck survey form through 6.0 fails to validate write passwords on submission endpoints, enforcing the check only on the front end. Remote unauthenticated attackers can submit form entries directly to public submission APIs without providing the password by using the form key from share links. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2026-100306? +

CVE-2026-100306 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0039, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-100306? +

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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