Cyber Resilience

CVE-2026-40935

Wwbn Avideo ≤ 29.0

Public PoC
Published
21 April 2026
Modified
23 April 2026
Patch / advisory
View advisory
CVSS Score v3.1 5.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS Score 0.0022 12th percentile
Risk Priority 43 floored blend · peak EPSS

Summary

CVE-2026-40935 is a medium-severity Guessable CAPTCHA (CWE-804) vulnerability in Wwbn Avideo. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Password Guessing (T1110.001); ranked at the 12th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability Data

WWBN AVideo is an open source video platform. In versions 29.0 and prior, `objects/getCaptcha.php` accepts the CAPTCHA length (`ql`) directly from the query string with no clamping or sanitization, letting any unauthenticated client force the server to generate a 1-character…

more

CAPTCHA word. Combined with a case-insensitive `strcasecmp` comparison over a ~33-character alphabet and the fact that failed validations do NOT consume the stored session token, an attacker can trivially brute-force the CAPTCHA on any endpoint that relies on `Captcha::validation()` (user registration, password recovery, contact form, etc.) in at most ~33 requests per session. Commit bf1c76989e6a9054be4f0eb009d68f0f2464b453 contains a fix.

CWE(s)
CWE-804

Related Threats

MITRE ATT&CK Enterprise Techniques

T1110.001 Password Guessing Credential Access
Adversaries with no prior knowledge of legitimate credentials within the system or environment may guess passwords to attempt access to accounts.
attack.mitre.org →
T1110.003 Password Spraying Credential Access
Adversaries may use a single or small list of commonly used passwords against many different accounts to attempt to acquire valid account credentials.
attack.mitre.org →
T1110 Brute Force Credential Access
Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-33763Same product: Wwbn Avideo
CVE-2023-49810Same product: Wwbn Avideo
CVE-2023-49599Same product: Wwbn Avideo
CVE-2023-50172Same product: Wwbn Avideo
CVE-2023-49589Same product: Wwbn Avideo
CVE-2020-37172Same product: Wwbn Avideo
CVE-2020-37158Same product: Wwbn Avideo
CVE-2026-33688Same product: Wwbn Avideo
CVE-2026-33488Same product: Wwbn Avideo
CVE-2026-45620Same product: Wwbn Avideo

Affected Assets

wwbn
avideo
≤ 29.0

Mitigating Controls

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure development practices directly require non-guessable CAPTCHA implementations.

PR.AA-03 partial match
prevents

Strong authentication practices include effective CAPTCHA challenges to block automated actors.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect weak CAPTCHA implementations before deployment.

A.8.26 Application security requirements partial match
prevents

Application security requirements mandate effective CAPTCHA challenges that cannot be easily bypassed by bots.

A.8.28 Secure coding partial match
prevents

Secure coding practices ensure CAPTCHA logic is resistant to automated recognition or guessing attacks.

A.8.5 Secure authentication partial match
prevents

Strong authentication mechanisms include robust CAPTCHA implementations that resist automated guessing.

References