Resource exhaustion in Litespeedtech Litespeed Web Adc
CVE-2025-54939
LiteSpeed QUIC (LSQUIC) Library before 4.3.1 has an lsquic_engine_packet_in memory leak.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.008 (55.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 55.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: +0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/litespeedtech/lsquic/blob/70486141724f85e97b08f510673e29f399bbae8f/C… (Release Notes)
- github.com/litespeedtech/lsquic/commit/4cd9252e77fb4a36b572e2167a84067d603d3b23 (Release Notes)
- www.imperva.com/blog/quic-leak-cve-2025-54939-new-high-risk-pre-handshake-remot… (Exploit, Third Party Advisory)
- blog.litespeedtech.com/2025/08/18/litespeed-security-update/ (Vendor Advisory)
Frequently asked questions
- What is CVE-2025-54939?
- CVE-2025-54939 is a medium-severity vulnerability in Litespeedtech Litespeed Web Adc, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.3/10. Published 2025-08-01.
- How severe is CVE-2025-54939?
- Medium severity. CVSS v3 base score is 5.3 out of 10.
- Is CVE-2025-54939 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.