CVE-2026-121553

    Dashboard / Vulnerabilities / CVE-2026-121553

    CVE-2026-121553

    Published: 3 Nov 2026Last Modified: 8 Nov 2026

    Summary: Cotonti through 1.0.0 Predictable Validation Tokens via md5(microtime())

    Details: Cotonti through 1.0.0 generates registration and email-change validation tokens with md5(microtime()), allowing attackers to bypass email-ownership verification by predicting tokens. Attackers can derive the generation time from the HTTP Date header and compute candidate tokens offline. They then submit these tokens to the users.register.php validate handler to activate accounts or confirm email addresses they do not control.

    References: https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/121xxx/CVE-2026-121553.json, https://nvd.nist.gov/vuln/detail/CVE-2026-121553, https://www.vulncheck.com/advisories/cotonti-through-1.0.0-predictable-validation-tokens-via-md5-microtime, https://github.com/Cotonti/Cotonti/issues/1904, https://github.com/Cotonti/Cotonti/pull/1905, https://github.com/Cotonti/Cotonti, https://github.com/Cotonti/Cotonti/blob/1.0.0/modules/users/inc/users.functions.php#L97, https://github.com/Cotonti/Cotonti/blob/1.0.0/modules/users/inc/users.profile.php#L116, https://github.com/Cotonti/Cotonti/blob/1.0.0/modules/users/inc/users.register.php#L148

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 0
    Fixed -None

    Affected versions

    1.0.0

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    CVE-2026-121553 | CVE-DB