Description
A flaw was found in Netty's HTTP/2 HpackEncoder. A remote attacker can exploit this by sending HTTP/2 SETTINGS frames with a very large MAX_HEADER_TABLE_SIZE. This causes the HpackEncoder to store an excessive number of unique headers, leading to increased CPU usage and memory consumption, ultimately resulting in a Denial of Service (DoS).
References10
- access.redhat.com/errata/RHSA-2026:69440
- access.redhat.com/errata/RHSA-2026:69470
- access.redhat.com/errata/RHSA-2026:83612
- access.redhat.com/errata/RHSA-2026:95221
- 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/security/cve/CVE-2026-93492
- bugzilla.redhat.com/show_bug.cgi?id=2536895
Metrics
- CVSS 3.1
-
5.3
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - EPSS — exploit probability
- 0% percentile: 42 · as of 8 November 2026
- CWE
- CWE-1035
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.