Cotonti: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
CVE-2026-93868 is a high-severity use of cryptographically weak pseudo-random number generator (PRNG) vulnerability in Cotonti, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Cotonti versions: 1.0.0 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.73% chance of exploitation within 30 days, higher than 55% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Cotonti you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.2 | Critical | CNA (vulncheck.com) |
| CVSS 3.1 | 8.1 | High | CNA (vulncheck.com) |
Official description
Cotonti through 1.0.0 derives password recovery validation tokens from md5(microtime()) in users.passrecover.php, creating a predictable token space of approximately one million values per second. Unauthenticated attackers can read the server Date header, precompute candidate tokens within a narrow time window, and probe them against the passrecover authentication endpoint to reset any account password including administrators.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG's algorithm is not cryptographically strong.
How developers prevent this class of flaw
- Use functions or hardware which use a hardware-based random number generation for all crypto. This is the recommended solution. Use CyptGenRandom on Windows, or hw_rand() on Linux.
More Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) vulnerabilities (CWE-338)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Other vulnerabilities in Cotonti
- 7.5 High severity
- 9.8 Critical severity
- 7.6 High severity
- 8.8 High severity
- 7.6 High severity
- 8.1 High severity
Recent Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) vulnerabilities
- 8.1 High severity
- 7.5 High severity
- 9.1 Critical severity
- 7.5 High severity
- 8.3 High severity
- 9.1 Critical severity
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