Cyber Resilience

CVE-2026-23837

Access Control in Franklioxygen Mytube ≤ 1.7.66

Published
19 January 2026
Modified
02 February 2026
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0057 44th percentile
Risk Priority 72 floored blend · peak EPSS

Summary

CVE-2026-23837 is a critical-severity Incorrect Authorization (CWE-863) vulnerability in Franklioxygen Mytube. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 44th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-25 (Reference Monitor) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-23837 is an authentication bypass vulnerability in the roleBasedAuthMiddleware of MyTube, a self-hosted downloader and player for video websites. The flaw affects version 1.7.65 and potentially earlier versions, impacting all instances where loginEnabled is set to true. It occurs when unauthenticated requests omit the authentication cookie, leaving req.user undefined, which causes the middleware to incorrectly pass the request to downstream handlers instead of blocking it. The vulnerability is rated CVSS 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) and maps to CWE-863 (Incorrect Authorization).

Unauthenticated remote attackers can exploit this vulnerability over the network with low complexity and no privileges required. By simply omitting the authentication cookie in requests, attackers bypass mandatory authentication checks, gaining unauthorized access to protected routes. This enables them to access and modify application settings via the /api/settings endpoint, change administrative and visitor passwords, and interact with other routes dependent on this middleware, potentially leading to full compromise of the MyTube instance.

The vulnerability is patched in MyTube version 1.7.66, which modifies the roleBasedAuthMiddleware to explicitly block unauthenticated requests with a 401 Unauthorized response instead of calling next(). MyTube maintainers, via their GitHub security advisory (GHSA-cmvj-g69f-8664) and commit (f85ae9b0d6e4a6480c6af5b675a99069d08d496e), urge users to upgrade to at least version 1.7.64 immediately. For those unable to upgrade, mitigations include restricting network access to /api/ endpoints using a firewall or reverse proxy like Nginx to allow only trusted IP addresses, or manually editing the source code to enforce a 401 error when req.user is undefined.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

MyTube is a self-hosted downloader and player for several video websites. A vulnerability present in version 1.7.65 and poetntially earlier versions allows unauthenticated users to bypass the mandatory authentication check in the roleBasedAuthMiddleware. By simply not providing an authentication cookie…

more

(making req.user undefined), a request is incorrectly passed through to downstream handlers. All users running MyTube with loginEnabled: true are impacted. This flaw allows an attacker to access and modify application settings via /api/settings, change administrative and visitor passwords, and access other protected routes that rely on this specific middleware. The problem is patched in v1.7.66. MyTube maintainers recommend all users upgrade to at least version v1.7.64 immediately to secure their instances. The fix ensures that the middleware explicitly blocks requests if a user is not authenticated, rather than defaulting to next(). Those who cannot upgrade immediately can mitigate risk by restricting network access by usi a firewall or reverse proxy (like Nginx) to restrict access to the /api/ endpoints to trusted IP addresses only or, if they are comfortable editing the source code, manually patch by locating roleBasedAuthMiddleware and ensuring that the logic defaults to an error (401 Unauthorized) when req.user is undefined, instead of calling next().

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
T1548.002 Bypass User Account Control Privilege Escalation
Adversaries may bypass UAC mechanisms to elevate process privileges on system.
T1548.003 Sudo and Sudo Caching Privilege Escalation
Adversaries may perform sudo caching and/or use the sudoers file to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-33735Same product: Franklioxygen Mytube
CVE-2026-24139Same product: Franklioxygen Mytube
CVE-2026-24140Same product: Franklioxygen Mytube
CVE-2026-23848Same product: Franklioxygen Mytube
CVE-2026-33890Same product: Franklioxygen Mytube
CVE-2026-33935Same product: Franklioxygen Mytube
CVE-2024-39690Shared CWE-863
CVE-2023-1979Shared CWE-863
CVE-2024-10295Shared CWE-863
CVE-2026-41375Shared CWE-863

Affected Assets

franklioxygen
mytube
≤ 1.7.66

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

AC-3 directly requires correct enforcement of authorization decisions on every access request, structurally preventing incorrect checks.

AC-24 ensures access-control decisions are made and applied consistently, reducing the chance of an incorrect authorization result.

A reference monitor that is always invoked and tamper-proof forces every authorization decision through a verified, correct path.

Least-privilege assignments shrink the set of authorizations that must be checked correctly, limiting exposure to flawed checks.

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.AA-05 mostly match
prevents

Defining, enforcing, and reviewing access authorizations and least privilege directly prevents incorrect authorization checks.

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.

prevents

Requiring consistency between access rights and classification plus formal approval steps ensures that the authorization logic correctly distinguishes between entities that should and should not be granted access.

prevents

Enforcing policy-driven approval and role-change reviews stops incorrect or stale authorization decisions from remaining in effect after job changes or terminations.

prevents

By tying access rights to identity, device, location and classification, the control reduces the likelihood that an authorization decision will be based on an incorrect or bypassed policy.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248581 OL 8 must require users to provide a password for privilege escalation. prevents CWE-863
  • V-252656 The OL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-863
RHEL 7 (1 rule)
  • V-204430 The Red Hat Enterprise Linux operating system must be configured so that users must re-authenticate for privilege escalation. prevents CWE-863
RHEL 8 (1 rule)
  • V-251712 The RHEL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-863

References