CVE-2026-93558
| Severity | 7.5 High CVSS 3.1 |
|---|---|
| Weakness | CWE-1035 |
| Published | 18 Sep 2026 |
| Updated | 6 Nov 2026 |
Published 56 days ago. NVD often adds the list of affected products days or weeks after a CVE is published, and the other sources we check lag too. The scope and status here may change.
Description
A flaw was found in Netty's WebSocketServerExtensionHandler. A remote, unauthenticated attacker can exploit this vulnerability by using HTTP/1.1 pipelining to send requests faster than the application can respond. This leads to an unbounded growth of a per-connection queue, consuming excessive memory. Eventually, this can cause the Java Virtual Machine (JVM) to exhaust its heap, resulting in a Denial of Service (DoS) for the affected server.
Exploitation status
Proof of concept only
A proof of concept exists, but no reviewed exploit catalogue lists this CVE.
Exploitation status
- CISA KEV not listed
- VulnCheck KEV not listed
- CISA Vulnrichment exploitation: poc CISA recorded that an exploit has been demonstrated. Automatable: yes, technical impact: partial.
- Indexed PoC none indexed
- EPSS 1.2% chance in 30 days
Waratek protection
Within Waratek scope. In the sources we check, nobody has published exploit code for this CVE or reported it being exploited.
A public code fix exists.
- Protection none
- Action unverified
- Review automated Upstream data
- Record active
| Decided by | Exploit code for this candidate, published in a reviewed catalogue or a GitHub repository with 5 or more stars, or in use per CISA or VulnCheck; not only a CISA verdict, a forecast, or nothing at all |
|---|---|
| Finding | This CVE is not listed in CISA KEV or VulnCheck KEV, CISA Vulnrichment records no active exploitation, no reviewed exploit catalogue carries an entry for it, and no GitHub PoC repository for it has 5 or more stars. Nobody has published exploit code worth tracing, so it is not a candidate for a rule ahead of the ones where somebody has; an upstream fix path does exist, so the remediation half of the candidacy still holds. This is a statement about what has been published, not about whether the defect is reachable or serious. |
| Candidate fix | https://bugzilla.redhat.com/show_bug.cgi?id=2536932 : a Red Hat bug: the triage, which links onward to the fix |
References
Timeline
Timeline
| Published | 2026-09-18 | By the CVE Program. |
|---|---|---|
| NVD record modified | 2026-11-06 | NVD's own last-modified date for this record. |