High severity · published Aug 1, 2025
CVE-2025-54939
LiteSpeed QUIC (LSQUIC) Library before 4.3.1 has an lsquic_engine_packet_in memory leak
7.5
CVSS
0.8%
EPSS
No
On KEV
Description
LiteSpeed QUIC (LSQUIC) Library before 4.3.1 has an lsquic_engine_packet_in memory leak.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.8% · higher than 56% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LW
Litespeed Web Adc · Litespeedtech
before 3.3.1 · source: NVD
LW
Litespeed Web Server · Litespeedtech
before 6.3.4 · source: NVD
LS
Lsquic · Litespeedtech
before 4.3.1 · source: NVD
OP
Openlitespeed · Litespeedtech
before 1.8.4 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-54939
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-54939
Vendor Advisory
https://blog.litespeedtech.com/2025/08/18/litespeed-security-update/
Release Notes
https://github.com/litespeedtech/lsquic/blob/70486141724f85e97b08f510673e29f399bbae8f/CHANGELOG#L1-L3
Release Notes
https://github.com/litespeedtech/lsquic/commit/4cd9252e77fb4a36b572e2167a84067d603d3b23
Exploit
https://www.imperva.com/blog/quic-leak-cve-2025-54939-new-high-risk-pre-handshake-remote-denial-of-service-in-lsquic-quic-implementation/