CVE-2026-15565
| Severity | 7.5 High CVSS 3.1 |
|---|---|
| Weakness | CWE-120 |
| Published | 11 Aug 2026 |
| Updated | 1 Nov 2026 |
Description
A flaw was found in Undertow. A remote attacker can cause Out of Memory on websockets endpoint without authentication on any @ServerEndpoint class that has any @OnMessage method. This allows an attacker to cause Denial of Service attack without authentication and using only a standard WebSocket handshake.
Exploitation status
No public exploit
No exploit has been reported in the sources we check.
Exploitation status
- CISA KEV not listed
- VulnCheck KEV not listed
- CISA Vulnrichment exploitation: none
- Indexed PoC none indexed
- EPSS 1.0% 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=2490628 : a Red Hat bug: the triage, which links onward to the fix |
References
Timeline
Timeline
| Published | 2026-08-11 | By the CVE Program. |
|---|---|---|
| NVD record modified | 2026-11-01 | NVD's own last-modified date for this record. |