CVE-2025-7394Network attack vector

Predictable random values via inherited Hash-DRBG state

Published Jul 18, 2025 · Updated Jul 21, 2025

Weak random number generation in wolfSSL 3.15.0 through 5.8.0 allows attackers to predict RAND_bytes() output after a process fork. The OpenSSL compatibility layer leaves parent and child processes with the same Hash-DRBG state because RAND_poll() does not reseed it after fork(). Exposure requires an application to call RAND_bytes() after fork; internal TLS operations use a separate random-number path and are unaffected.

CVSS severity7.0
High
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Weak random number generation in wolfSSL 3.15.0 through 5.8.0 allows attackers to predict RAND_bytes() output after a process fork. The OpenSSL compatibility layer leaves parent and child processes with the same Hash-DRBG state because RAND_poll() does not reseed it after fork(). Exposure requires an application to call RAND_bytes() after fork; internal TLS operations use a separate random-number path and are unaffected.

The record

CVE
CVE-2025-7394
Published
Jul 18, 2025
Updated
Jul 21, 2025
Vendor
wolfSSL
Product
wolfSSL
Classifications
CWE-200, CWE-338
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 18, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.15.0 <=5.8.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

wolfSSL · wolfSSLversion=3.15.0 <=5.8.0

Published CVSS scores

9.8NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.0wolfSSLCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
CWE-338Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo