CVE-2025-24947 (CVSS 5.3)

Description

A hash collision vulnerability (in the hash table used to manage connections) in LSQUIC (aka LiteSpeed QUIC) before 4.2.0 allows remote attackers to cause a considerable CPU load on the server (a Hash DoS attack) by initiating connections with colliding Source Connection IDs (SCIDs). This is caused by XXH32 usage.

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CVSS v3.1 Score

5.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Weakness Type (CWE)

CWE-407 CWE-407

References

Other References

https://github.com/litespeedtech/lsquic/releases/tag/v4.2.0 https://github.com/ncc-pbottine/QUIC-Hash-Dos-Advisory https://xxhash.com

Frequently Asked Questions

What is CVE-2025-24947? +

A hash collision vulnerability (in the hash table used to manage connections) in LSQUIC (aka LiteSpeed QUIC) before 4.2.0 allows remote attackers to cause a considerable CPU load on the server (a Hash DoS attack) by initiating connections with colliding Source Connection IDs (SCIDs). This is caused by XXH32 usage. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2025-24947? +

CVE-2025-24947 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

How do I check if I'm vulnerable to CVE-2025-24947? +

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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