Description
LiteSpeed QUIC (LSQUIC) Library before 4.3.1 has an lsquic_engine_packet_in memory leak.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| litespeedtech | LSQUIC | < 4.3.1 | 4.3.1 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
GitHub 1 repository
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yohannslm/CVE-2025-54939 ★ 1 · Aug 27, 2025
POC for CVE-2025-54939. ~ forcibly loads 200MiB/s in server's memory
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
References
- https://github.com/litespeedtech/lsquic/blob/70486141724f85e97b08f510673e29f399bbae8f/CHANGELOG#L1-L3
- https://github.com/litespeedtech/lsquic/commit/4cd9252e77fb4a36b572e2167a84067d603d3b23
- https://www.imperva.com/blog/quic-leak-cve-2025-54939-new-high-risk-pre-handshake-remote-denial-of-service-in-lsquic-quic-implementation/
- https://blog.litespeedtech.com/2025/08/18/litespeed-security-update/