CVE-2026-46488: motionEye: Authentication possible via password hash

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
• EPSS 0.5%, percentile 39: FIRST’s model estimates a 0.5% chance of exploitation activity in the next 30 days, higher than 39% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes motioneye (PyPI) < 0.44.0, fixed in 0.44.0. Check your lockfile, including transitive dependencies.

What it is

motionEye (mEye) is an online interface for a piece of software called "motion," which is a video surveillance program with motion detection. Prior to 0.44.0, motionEye accepts the client-controlled meyeusername and meyepasswordhash cookies as authentication material without server-side session validation. An unauthenticated attacker who knows a target username and corresponding hash can set the cookies manually or cause them to be loaded by submitting blank credentials through the switch-user authentication flow, after which the server authenticates the attacker as that user. The administrator username and password-hash value are stored in /etc/motioneye/motion.conf, which is globally readable by default, allowing a local shell user to obtain reusable administrator credential material. Successful impersonation can enable account lockout, password changes and persistence, data enumeration, data destruction, and data exfiltration. This issue is fixed in version 0.44.0.

From the GitHub advisory

Summary An authentication bypass vulnerability exists due to improper trust in client-controlled cookies. The application accepts user-supplied cookie values containing a username and password-hash-derived value as sufficient authentication material. These cookies can be set or modified prior to login, allowing an unauthenticated attacker to impersonate arbitrary users without knowledge of the plaintext password. This issue stems from the absence of server-side validation of authentication state and reliance on attacker-controlled cookie data

Details The vulnerability arises because the application accepts the client-supplied cookies named meyepasswordhash and meyeusername as sufficient authentication material. The server does not validate these values against a server-side session or enforce proper authentication checks before establishing an authenticated state. As a result, an unauthenticated attacker can set or modify these cookies to impersonate another user if the target username and corresponding hash are known.

These cookies normally appear after using the "switch user" functionality; however, they can be added manually prior to authentication using standard browser tools (e.g., developer tools or cookie editors) or dynamically loaded by submitting blank credentials. When supplied, the server accepts them and authenticates the attacker as the specified user bypassing the intended authentication flow

Additionally, the password-hash value and username for the admin account used by the application is stored in /etc/motioneye/motion.conf which is globally readable by default on the local system. This means any local user with shell access can obtain a valid hash and values and use them to impersonate the admin via the cookie manipulation described above. While local access is required to retrieve the hash, this significantly lowers the barrier to exploitation in multi-user environments.

PoC Starting state unauthenticated with no cookies:

Weakness type: CWE-256, CWE-287, CWE-328, CWE-836.

Product: motioneye (PyPI) · Assigned by: GitHub_M · Published: 2026-09-15

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: present (depends on deployment conditions)
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation poc, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.46% probability of exploitation activity in the next 30 days; percentile 39.

Timeline

• 2026-06-22 — GitHub-reviewed advisory GHSA-r3cw-c95m-wfh9 published (critical)
• 2026-09-15 — CVE record published by GitHub_M
• 2026-09-17 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-r3cw-c95m-wfh9 github.com
2. CVE.org record CVE-2026-46488 cve.org
3. NVD entry CVE-2026-46488 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com
4. github.com github.com

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