Description
A flaw was found in Netty. SpdySessionHandler accepts an unlimited number of concurrent remote-initiated streams because localConcurrentStreams defaults to Integer.MAX_VALUE and the handler provides no API to change it. A remote peer can open a SPDY connection and send a large number of SYN_STREAM frames with FLAG_FIN=0, causing unbounded heap and direct memory allocation that can lead to JVM OutOfMemoryError and a denial of service.
References10
- access.redhat.com/errata/RHSA-2026:69440
- access.redhat.com/errata/RHSA-2026:69470
- access.redhat.com/errata/RHSA-2026:70257
- access.redhat.com/errata/RHSA-2026:83612
- access.redhat.com/errata/RHSA-2026:95759
- access.redhat.com/errata/RHSA-2026:95760
- access.redhat.com/errata/RHSA-2026:95761
- access.redhat.com/errata/RHSA-2026:95762
- access.redhat.com/errata/RHSA-2026:95887
- access.redhat.com/security/cve/CVE-2026-93488
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 1% percentile: 62 · as of 8 November 2026
- CWE
- CWE-770
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.