Cotonti through 1.0.0 generates registration and email-change validation tokens with md5(microtime()), allowing
Source GCVE Database
Not known to be exploited · CVSS 6.3 Medium.
Data as of 3 Nov 2026, 20:00 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 6.3 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 4.8 |
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 3 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| cotonticotonti | Affected
| Fixed in– |
Packagistcotontipkg:composer/cotontiOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Users should monitor the vendor advisory for updates. Until a fix is available, consider implementing additional verification steps or replacing the token generation mechanism with a cryptographically secure random function.
Description
Cotonti versions through 1.0.0 use md5(microtime()) to generate registration and email-change validation tokens. This method allows attackers to predict tokens by deriving the generation time from the HTTP Date header and computing candidate tokens offline. Exploiting this vulnerability enables bypassing email-ownership verification, potentially activating accounts or confirming email addresses without control over them.
References
- nvd.nist.gov/vuln/detail/CVE-2026-121553 (opens in a new tab)
- github.com/Cotonti/Cotonti/issues/1904 (opens in a new tab)
- github.com/Cotonti/Cotonti/pull/1905 (opens in a new tab)
- github.com/Cotonti/Cotonti (opens in a new tab)
- github.com/Cotonti/Cotonti/blob/1.0.0/modules/users/inc/users.functions.php (opens in a new tab)
- github.com/Cotonti/Cotonti/blob/1.0.0/modules/users/inc/users.profile.php (opens in a new tab)
- github.com/Cotonti/Cotonti/blob/1.0.0/modules/users/inc/users.register.php (opens in a new tab)
- vulncheck.com/advisories/cotonti-through-1.0.0-predictable-validation-tokens-via-md5-microtime (opens in a new tab)