CVE-2025-27209 (CVSS 7.5)

Description

The V8 release used in Node.js v24.0.0 has changed how string hashes are computed using rapidhash. This implementation re-introduces the HashDoS vulnerability as an attacker who can control the strings to be hashed can generate many hash collisions - an attacker can generate collisions even without knowing the hash-seed. * This vulnerability affects Node.js v24.x users.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-407 CWE-407

References

Other References

https://nodejs.org/en/blog/vulnerability/july-2025-security-releases http://www.openwall.com/lists/oss-security/2025/07/22/2

Frequently Asked Questions

What is CVE-2025-27209? +

The V8 release used in Node.js v24.0.0 has changed how string hashes are computed using rapidhash. This implementation re-introduces the HashDoS vulnerability as an attacker who can control the strings to be hashed can generate many hash collisions - an attacker can generate collisions even without knowing the hash-seed. * This vulnerability affects Node.js v24.x users. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2025-27209? +

CVE-2025-27209 has a CVSS v3.1 score of 7.5 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-2025-27209? +

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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