Allocation of Resources Without Limits or Throttling in Netty - CVE-2026-48748
Published: June 8, 2026
Vulnerability identifier: #VU133442
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-48748
CWE-ID: CWE-770
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to allocation of resources without limits or throttling in io.netty.handler.codec.http3.QpackDecoder#shouldWaitForDynamicTableUpdates when processing HTTP/3 header blocks that reference dynamic table entries the server has not yet received. A remote attacker can send specially crafted HTTP/3 requests to cause a denial of service.
Only servers with QPACK dynamic tables enabled are vulnerable when the blocked streams setting is left at its default value of 0.
Affected software
Netty
How to mitigate CVE-2026-48748
Install security update from vendor's website.
Netty - update to 4.2.15