CVE-2025-42959

HIGH
Published Jul 8, 2025 Modified Apr 15, 2026 CWE-308

Description

An unauthenticated attacker may exploit a scenario where a Hashed Message Authentication Code (HMAC) credential, extracted from a system missing specific security patches, is reused in a replay attack against a different system. Even if the target system is fully patched, successful exploitation could result in complete system compromise, affecting confidentiality, integrity, and availability.

CVSS v3.1 Score

8.1
HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-308 CWE-308

References

Frequently Asked Questions

What is CVE-2025-42959? +
An unauthenticated attacker may exploit a scenario where a Hashed Message Authentication Code (HMAC) credential, extracted from a system missing specific security patches, is reused in a replay attack against a different system. Even if the target system is fully patched, successful exploitation could result in complete system compromise, affecting confidentiality, integrity, and availability. It has a CVSS v3.1 base score of 8.1 (HIGH).
How severe is CVE-2025-42959? +
CVE-2025-42959 has a CVSS v3.1 score of 8.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.
How do I check if I'm vulnerable to CVE-2025-42959? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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