CVE-2025-54939

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.80% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 56.1% of scored records. A rank, not a probability.

NVD base score

7.5 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2025-08-01 00:00Z1 YR AGO

Last updated

2025-08-20 19:55Z1 YR AGO

Reserved

2025-08-01

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Medium (CVSS 5.3)

CNA CVSS vector

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

Weaknesses

• CWE-770Allocation of Resources Without Limits or ThrottlingBase
• CWE-401Missing Release of Memory after Effective LifetimeVariant

Data version

5.1

Document digest

d9d6feb085880be7ac1bc311e258f2828ab769bf2d101d48a8baee3e67af46fa

• github.comhttps://github.com/litespeedtech/lsquic/blob/70486141724f85e97b08f510673e29f399bbae8f/CHANGELOG#L1-L3
• github.comhttps://github.com/litespeedtech/lsquic/commit/4cd9252e77fb4a36b572e2167a84067d603d3b23
• www.imperva.comhttps://www.imperva.com/blog/quic-leak-cve-2025-54939-new-high-risk-pre-handshake-remote-denial-of-service-in-lsquic-quic-implementation/
• blog.litespeedtech.comhttps://blog.litespeedtech.com/2025/08/18/litespeed-security-update/